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Cognitive performance during irrelevant speech: Effects of speech intelligibility and office-task characteristics
Abstract
In open-plan offices, it is common that colleagues talk in the background while non-auditory tasks need to be performed. The aims of the present study were, first, to investigate how much cognitive performance is impaired by irrelevant background speech with varying degree of speech intelligibility, and second, to determine whether some office-related tasks are more susceptible to distraction than others. We tested a model developed by Hongisto [1] which predicts the decrease of cognitive performance as a function of speech intelligibility, depicted by the Speech Transmission Index (STI). Our results showed that the shape of the STI–performance curve, and the magnitude of the performance decrease, depend on task type. A semantic short-term memory task (i.e. word memory) was more sensitive to disruption by speech than a mathematical task. A word fluency task (i.e. retrieval of information from semantic long term memory) was not influenced by varying speech intelligibility. Moreover, performance on an Information search task was impaired by speech with high intelligibility only. The steepest slope in performance decrease appeared at a lower speech intelligibility value than predicted by Hongisto [1]. It also varied between cognitive tasks. The results of this study are useful in determining an appropriate target level for acoustic design in offices: This work demonstrates that attempts to minimize speech intelligibility will yield increases in cognitive performance with a varying degree, depending on the type of focal task.
... A large number of studies examined the effects of speech intelligibility on occupants' work performance [19][20][21]. The Speech Transmission Index (STI), an objective parameter of speech intelligibility, has been frequently used in previous studies to research the relationship between speech intelligibility and work performance [8,14,22]. ...
... For instance, Haka et al. [19] examined how STI conditions (STI = 0.10, 0.35 and 0.65) affect occupants' work performance in Finnish environments. Jahncke et al. [20] tested how much work performance is reduced by speech noise with five levels of speech intelligibility (STI = 0.08, 0.16, 0.23, 0.34, and 0.71) in the Swedish environment. Renz et al. [23] conducted a laboratory experiment to study the effects of eight STI conditions (STI = 0.10 to 0.33) on occupants' work performance and perceived sound annoyance in the German environment by changing the speech-to-noise ratio (SNR) and masking sounds. ...
... and the performance decrease starts at the STI of 0.38 and reaches a maximum at the STI of 0.65. However, a previous study [20] in the Swedish environment indicated that the performance decrease of the serial recall task occurs within the STI range of 0.23-0.34. In addition, the study of Kang and Ou [8] found a difference between Chinese and non-Chinese environments in terms of the effects of STI values on work performance. ...
Speech noise can reduce occupants' work performance in open-plan offices. Some models have been created to predict the effect of speech of different intelligibility on work performance. However, few of them consider the effects of speech intelligibility in Chinese environments. This study aims to develop a model that evaluates how much work performance is decreased by speech noise with different intelligibility in Chinese open-plan offices. A laboratory experiment has been conducted in this paper to determine the effects of different speech intelligibility on occupants' objective performance of the serial recall task and perceived speech disturbance in Chinese open-plan offices. Then, a prediction model was developed by analyzing the data from this experiment and two previous studies. These two studies researched the effects of the Speech Transmission Index (STI, an objective parameter of speech intelligibility) on the serial recall performance in Chinese environments. According to the prediction model of serial recall performance in Chinese environments, performance decrease occurs within the STI range of 0.31–0.47. The comparison of curves between STI and DP with previous studies shows that the STI range for serial recall performance variation in Chinese environments is narrower than in non-Chinese language environments. Furthermore, the DP average change rate of serial recall tasks in Chinese environments is not less compared to non-Chinese environments, although the effect of speech noise on serial recall performance is lower in the Chinese environment.
... However, there is no evidence for defining target values for the STI and the two distances. These two values were chosen without considering the variability of the experimental data represented in Fig. 1 [15,[18][19][20][21][22][23]. These data are taken from the articles discussing the relation between decrease in performance and STI. ...
... As a result, this value cannot be defined as a ''target value" used for the definition of the distraction distance. In addition, studies using STI values lower than 0.7 may have used different protocols which can explain this variability between the experiments of the Fig. 1 [21]. This can complicate the comparison of the results from these different experiments. ...
... Moreover, some of the results presented in Fig. 1, such as those presented in Jahncke et al. (2013) [21] fit to the plateau effect described by the Hongisto model [15]. However, for others, no saturation was observed at high STI values. ...
It seems now accepted that speech noise in open plan offices is the main source of annoyance for employees. The aim of the present study is to test in a laboratory the effect of different sound conditions representative of ambient noise in open plan offices, while the participants perform a task closer to the everyday open-plan office work. Forty-five subjects between 18 and 58 years old participated to the experiment. They were exposed to four controlled sound conditions, made of intelligible speech superimposed to babble noise: equivalent modulation index MAeq and overall level LAeq were the two control factors (two levels each). The duration of the experiment for each condition was equivalent to the duration of half a workday (four hours for each condition). The task consisted in writing a review of four newspapers. During each half-day, the self-reported mental fatigue and the perception of sound environment were evaluated several times. The statistical analyses were performed with respect to three factors, the two sound characteristics (MAeq and LAeq) and the time of the day. The results show that a high intelligibility, which corresponds to a high MAeq value, significantly increased the fatigue experienced by the participants. Lastly, the results of this experiment were compared to a previous experiment conducted by Kostallari et al. We concluded that, for all sound conditions, in both experiments, speech noise has a higher impact on the mental fatigue of the participants, compared to stationary noise or to the ?speech like? amplitude-modulated noise.
... However, there is no evidence for defining target values for the STI and the two distances. These two values were chosen without considering the variability of the experimental data represented in Fig. 1 [15,[18][19][20][21][22][23]. These data are taken from the articles discussing the relation between decrease in performance and STI. ...
... As a result, this value cannot be defined as a ''target value" used for the definition of the distraction distance. In addition, studies using STI values lower than 0.7 may have used different protocols which can explain this variability between the experiments of the Fig. 1 [21]. This can complicate the comparison of the results from these different experiments. ...
... Moreover, some of the results presented in Fig. 1, such as those presented in Jahncke et al. (2013) [21] fit to the plateau effect described by the Hongisto model [15]. However, for others, no saturation was observed at high STI values. ...
For employees working in open plan offices, speech noise is now recognised as the main source of disturbance. In the literature, a series of studies on open spaces have found that the increased speech intelligibility happens to decrease the performance during a short-term memory task. The theoretical model proposed by Hongisto relates the decreased performance (DP) to the Speech Transmission Index (STI). The model predicts that for STI values from 0.7 to 1, which correspond to a speech signal with an intelligibility of almost 100%, the DP remains constant at 7%, but few studies have examined the high end of this range. Here, we investigated the relationship between the DP and the STI by varying the STI up to 0.9. Fifty-five subjects between 25- and 59-years-of-age participated in the experiment. Subjects performed a short-term memory task in silence and in four different sound conditions (STI from 0.25 to 0.9). The task itself was personalised by prior measurement of mnemonic span. It was thus possible to define two different cognitive loads (low/high) based on the mnemonic span value determined for each subject. Subjects subjectively assessed the mental workload and sound annoyance at the end of each short-term memory task in each sound condition. Significant interactions between STI and DP, mental workload and sound annoyance were found. In addition, the age of subjects correlated significantly with their performance during the short-term memory task.
... Ces expériences sont réalisées, en majorité, à partir de tâches de mémoire à court-terme. Il semblerait que parmi les différentes études en laboratoire, les tâches de mémoire à court-terme soient les plus utilisées pour observer un effet des variations d'intelligibilité de la parole sur les performances (Brocolini, Parizet, & Chevret, 2016;Ebissou, Parizet, & Chevret, 2015;Ellermeier & Hellbruck, 1998;Haka et al., 2009;Jahncke, Hongisto, & Virjonen, 2013;Liebl, Assfalg, & Schlittmeier, 2016 Ce chapitre va présenter les modèles nécessaires pour pouvoir réaliser la partie expérimentale de cette thèse, constituée de deux expériences, une de courte durée et une de longue durée. ...
... Une synthèse des résultats de ces études est présentée ci-dessous. (Ellermeier & Hellbruck, 1998) Dans la continuité de la deuxième expérience (Ebissou, 2013), (Brocolini et al., 2016) Pour mettre en place une méthodologie pour le contrôle de la performance et personnalisation de la tâche, il faut déjà regarder de plus près les protocoles de mesures des expériences citées dans la partie précédente (Brocolini et al., 2016;Ebissou et al., 2015;Ellermeier & Hellbruck, 1998;Haka et al., 2009;Jahncke et al., 2013;. Premièrement, dans ces protocoles de mesure, deux types de tâches mnésiques différents sont utilisés. ...
... De la même façon, (S. J. et (Jahncke et al., 2013) font des expériences de durée plus ou moins égale à 60 min. Selon ...
Il est aujourd’hui accepté que le bruit de parole représente la principale source de gêne pour les employés des bureaux ouverts. L’objectif de ce travail est d’évaluer les effets psychophysiologiques de la parole intelligible sur les salariés effectuant une ou plusieurs tâches. Pour répondre à cet objectif, deux expériences ont été réalisées. La première a pour but d’évaluer le décrément de performance (DP) lors d’une tâche de sériation pour de fortes valeurs d’intelligibilité. L’indicateur acoustique choisi est le STI (« Speech Transmission Index »). Les résultats de l’étude menée auprès de cinquante-cinq participants montrent un effet du STI sur le DP. Cependant, cette expérience a une validité écologique réduite puisqu’elle est de courte durée et qu’elle est limitée à une tâche très spécifique. La deuxième expérience a donc pour but d’élaborer des tests en laboratoire plus proches des conditions de travail en bureau ouvert et d’étudier l’effet de la parole intelligible sur des indicateurs psychologiques. Trente-neuf participants ont participé à cette expérimentation. Plusieurs mesures telles que la fatigue psychologique, la gêne sonore et la charge mentale de travail ont été réalisées. Les participants ont été soumis à trois conditions sonores différentes (bruit stationnaire, bruit modulé et parole) durant trois journées. Chaque jour, les participants ont réalisé leur travail en étant exposés à la même condition sonore pendant 6h45min. Les résultats montrent un effet de la parole sur l’état psychologique des participants. La parole semble être la source de bruit la plus fatigante et la plus gênante. Elle entraine également une charge mentale supplémentaire. Au-delà des résultats de ces expériences, les modèles psychologiques mobilisés lors de cette thèse peuvent être adaptés pour mener des enquêtes in-situ afin d’évaluer et prévenir les risques psychologiques liés aux bruits dans les bureaux ouverts.
... Noise interference with speech comprehension results in problems with concentration, decreased working capacity, and stress reactions at work [20,21]. Many respondents have reported that noise exposure worsens work performance [22][23][24]. ...
... The correlation coefficients retrieved from different groups were tested against each other using Fisher's z transformation [50,51]. Lastly, [17][18][19][20][21][22][23][24][25][26][27] multiple regression analyses with all independent variables (noise sensitivity, type of job, and years of working) based on dummy variables were conducted to estimate their effects on the subjective adverse impacts of noise at construction sites. ...
... There was no significant difference between the LS and MS groups with regard to noise annoyance (p = 0.90). These results [17][18][19][20][21][22][23][24][25][26][27] indicate that noise sensitivity of construction managers could be a critical personal factor influencing the adverse impact of noise at construction sites. ...
This study aims to assess various perceived adverse effects of noise on construction sites according to the different stages and machinery used in the stages, and to examine whether or not personal-situational factors affect the judgment of managers regarding the adverse impact of noise at work through a self-reported survey method. Four primary construction stages and twenty-four types of construction machines were evaluated. The effects of personal (noise sensitivity) and situational (types of jobs, and years of working) factors on the adverse impacts of noise on annoyance, work performance, work safety, and speech interference at work were examined. The results show significant differences in perceived noise annoyance in the various construction stages. The demolition stage is the most annoying, followed by the foundation, earthwork, and concrete framing stages. In addition, the annoying equipment differs for each construction stage. A breaker, pile driver, and hammer compactor are rated as the most annoying construction machines in the demolition, foundation, and earthwork stages, respectively. Individual noise sensitivity appears to have the most significant influence on the adverse impacts of noise on annoyance, work performance, work safety, and speech interference. A high noise sensitivity group tends to judge construction noise to be more adverse than the rest. In addition, different interrelationships between the adverse items of noise are found across their types of jobs: building construction, civil construction, and safety management. The findings of this study will provide further knowledge to facilitate better noise management planning on construction sites.
... Language is a key factor when considering office acoustic environment. Recent studies [3,4] reveal, even under the same STI condition, the perceived speech intelligibility of different languages (such as English and Polish) differs between each other; and even for the same task, the effects of STI are quite different in different language environments. In China, open-plan offices have become pop-ular. ...
... Specifically, Condition 1.1 (referred to as "noMask_ noSN") was the condition without masking sound and speech noise (i.e., a quiet environment with the room background noise level of about 32 dB(A)); and Condition 1.2 (referred as "noMask_SN") was the condition without masking sound but with speech noise, with the STI value of 0.67, representing a condition of good speech intelligibility. Changing signal-to-noise ratio (SNR) by introducing masking sound is a common method to achieve different STI values of open-plan offices in laboratory studies [4,8]. In this study, masking sound was also used and 3 different STI values were achieved in the experiment. ...
... (3)The presence of speech noise has little effect on participants' performance of mental arithmetic, reading comprehension and proofreading, which is in agreement with the results in a Finnish environment [8,11] but different with those in a Swedish environment (the presence of speech noise was found to have significant impacts for reading comprehension [15] and proofreading [16] in a Swedish environment). (4) The variation of STI has little effect on participants' performance of mental arithmetic in this study; however, in a Swedish environment [4], it was found that the performance of this task in STI < 0.25 is significantly better than that in STI = 0.34. ...
The language used in an environment is a significant factor when examining the effects of speech intelligibility on work performance and acoustic comfort in open-plan offices. A laboratory experiment has been carried out in this paper to study the effects of speech noise and STI values in a Chinese open-plan office environment. Four cognitive tasks were tested in the experiment, and the objective performance and subject perceptions of 38 participants were examined under 5 different acoustic conditions. The results demonstrate the significant negative effects of speech noise on participants’ objective performance of serial recall task and subjective feelings about workplace (including perceived performance, work load, sound disturbance and acoustic comfort), and all these negative effects become stronger with the increase of STI. In addition, participants’ subjective perceptions are found to be more sensitive to the change of acoustic condition than their objective performance. Moreover, a comparison of these results and those of previous studies in non-Chinese environments shows there are some differences in the effects of speech noise and STI between Chinese and non-Chinese environments and therefore demonstrates again the importance of taking into consideration of language environment in the analysis of open-plan office acoustic problems.
... Employees in A-FOs should be able to, by choosing quiet workspaces, avoid distractions (Gerdenitsch et al., 2017) such as irrelevant speech and speech with high Speech Transmission Index (level of intelligibility of speech) found in open-plan offices by experimental and questionnaire studies (Jahncke, Hongisto, & Virjonen, 2013;Smith-Jackson & Klein, 2009). Longitudinal single case, and multiple case cross-sectional studies suggest that there are fewer distractions (Gerdenitsch et al., 2017;Seddigh, Berntson, Bodin Danielson, & Westerlund, 2014) or no difference (Morrison & Macky, 2017) after relocation to A-FOs than in open-plan offices. ...
... Crowding is a subjective psychological response to limited space (Stokols, 1972). Open-plan offices have shown lowered auditory privacy (Jahncke et al., 2013;Jahncke, Hygge, Halin, Green, & Dimberg, 2011;Kim & de Dear, 2013;Sundstrom, Burt, & Kamp, 1980), and lowered visual and informative privacy (Brennan, Chugh, & Kline, 2002;Sundstrom et al., 1980;Vischer, 2008) compared to cell offices. ...
... Employees in offices with diversity in acoustic settings were more satisfied with privacy, mental work conditions, work environment satisfaction and performance than those without (Study III). Hence, the results indicate that noise and lack of auditory privacy, which are key sources to dissatisfaction (Morrison & Macky, 2017) and reduced performance (Banbury & Berry, 1998;Hongisto, 2005;Jahncke et al., 2013), can be prevented by allocating spaces for different acoustic settings. The importance of diversity of workspaces for employee satisfaction is pointed out in a cross-case study (Brunia et al., 2016). ...
... For example, people suffered impatience, irritability in the acoustic environment when working with complex cognitive tasks, so ''do not make me impatient" and ''do not make me feel irritable" were mentioned by participants and they were identified as items to measure the quality of the acoustic environment, which turned out a people-oriented tool to measure the acoustic environment. Additionally, although some dimensions had been considered in previous studies (e.g., ''no heart rate" [26,35,54], ''annoyance" [18,27,32,55], ''decrease in productivity" [27,55,56]), several dimensions were firstly reported (e.g., ''no goose bumps", ''accompany me and make me not be lonely", ''do not give rise to the act or thought of resignation"), which enlarged the capacity of demand database, and new demand dimensions might contribute to understand the influence mechanism of the acoustic environment on people when they were working with complex cognitive tasks. ...
... For example, people suffered impatience, irritability in the acoustic environment when working with complex cognitive tasks, so ''do not make me impatient" and ''do not make me feel irritable" were mentioned by participants and they were identified as items to measure the quality of the acoustic environment, which turned out a people-oriented tool to measure the acoustic environment. Additionally, although some dimensions had been considered in previous studies (e.g., ''no heart rate" [26,35,54], ''annoyance" [18,27,32,55], ''decrease in productivity" [27,55,56]), several dimensions were firstly reported (e.g., ''no goose bumps", ''accompany me and make me not be lonely", ''do not give rise to the act or thought of resignation"), which enlarged the capacity of demand database, and new demand dimensions might contribute to understand the influence mechanism of the acoustic environment on people when they were working with complex cognitive tasks. ...
Noise has been proved to be a risk factor of physiological and psychological health. Creating a healthy acoustic environment is particularly important for people’s health and well-being. According to the former study, a healthy acoustic environment was expected to meet people’s subjective demands and the specific demands of people were proved to be closely associated with context. Based on the finding, the aims of this study are to explore people’s specific demands for a healthy acoustic environment and present a shortened questionnaire on people’s demands when working with complex cognitive tasks. Through focus group interviews, a total of 81 demands of people for a healthy acoustic environment were obtained. With a large sample questionnaire survey, some individualized demands were eliminated and the demands needed by most people were remained. Afterwards, a laboratory experiment was carried out and a shortened questionnaire on people’s demands for a healthy acoustic environment when working with complex cognitive tasks was proposed. Finally, the reliability and validity of the shortened questionnaire and its ability to differentiate various acoustic environments of working were tested. This study showed a detailed list of people’s demand for a healthy acoustic environment when working with complex cognitive tasks. In particular, the shortened questionnaire finally proposed in this study (DQ-HAEW8) could be used as a tool to measure the health level of acoustic environments when people were working with complex cognitive tasks in future.
... Background speech in offices deteriorates subjective wellbeing and work performance (e.g. [1][2][3][4][5]). The speech transmission index (STI) is suggested to predict both subjective noise disturbance and work performance (e.g. ...
... The speech transmission index (STI) is suggested to predict both subjective noise disturbance and work performance (e.g. [1,3,[5][6][7][8]). Using the STI is an established method applied during the design and development phase of openplan offices [7,9,10]. ...
Acoustical privacy is one of the most crucial, yet least satisfying aspects in open-plan offices. The assessment of acoustical conditions in occupied offices is challenging, and hence room acoustic parameters are commonly determined in unoccupied offices. This paper presents a new approach to apply a source-receiver matrix to determine the room acoustic parameters of open-plan offices similar to ISO 3382-3. The method is used to compare the effects of acoustic screens and wall absorption.
... This test environment was used to simulate a common mid-or large-sized open-plan office. 17,18 Four workstations (desks A, B, C, and D) were used as test positions, which were separated by 1.5 m high screens. The other two desks (E and F) were used as control consoles. ...
... Changing the signal-to-noise ratio (SNR) by introducing masking sound is a common method to achieve different STI values of open-plan offices in laboratory studies. 4,17 In this experiment, the masking sound (pink noise) was also used and five different STI values were achieved. The higher STI, the higher the intelligibility of the speech. ...
A laboratory experiment was conducted to study the effects of speech intelligibility on English scientific literature reading performance in Chinese open-plan offices (both the occupants' native language and ambient speech noise were Chinese). The objective performance and subject perceptions of 20 participants were tested under different speech intelligibility conditions. The results highlight the significant negative impact of speech noise on occupants' performance. Moreover, a comparison of these results and those of previous studies implies Chinese occupants engaged in English scientific literature reading tasks are more sensitive to the changes of speech intelligibility and have higher requirements for acoustic environment.
... Background speech impairs subjective well-being and work performance (e.g. [1,2,3,4,5]), and speech privacy is one of the most crucial, yet least satisfying aspects of the indoor environmental quality in office buildings [1]. The speech from colleagues' conversations or telephone calls are the most disturbing noise sources in open-plan offices [6,7,8]. ...
... STI is suggested to predict both subjective noise disturbance and work performance (e.g. [2,4,5,6,21,22]). Using the STI is an established method applied during the design and development phase of openplan offices [21,23,24]. ...
In Germany, the rating level is an important parameter to assess noise immissions in occupied offices. The rating level denotes the energy-equivalent sound pressure level during a measurement period with speech sounds and considers penalties for tonal, informational and impulsive constituents. There is little evidence that the rating level correlates with the performance and perceived annoyance of office workers. This study evaluates 89 different sound conditions under which subjects have to complete a short-term memory task and a questionnaire in laboratory conditions with respect to their relationships with the rating level. The relationships of the penalty for impulsiveness and the penalty for tonality or informational constituents with the rating level are analyzed separately. In addition, the penalty for tonality or informational constituents is substituted by percentile level statistics, namely the difference between the 10 th and 90 th percentile levels. In contrast to the penalty for tonality or informational constituents, this metric is objectively measurable. Using the rating level to assess the noise at office workplaces could be improved by using percentile level statistics to account for informational constituents. To improve the predictive validity, it is suggested to report the penalties separately.
... Estimated STI values based on L A95 and the regular STI values vary above 0.6 and despite of a change of intelligibility no change of performance is expected based on Hongisto's model. Some studies have shown that for some complex tasks, like writing [12], word memory and mathematics [67], the largest drop of performance occurs for even lower values of the STI than the original model of Hongisto [66] predicted. In Jahncke et al. [67] and Keus van de Poll et al. [12], the largest drop of performance occurred between STI values of 0.23 and 0.34. ...
... Some studies have shown that for some complex tasks, like writing [12], word memory and mathematics [67], the largest drop of performance occurs for even lower values of the STI than the original model of Hongisto [66] predicted. In Jahncke et al. [67] and Keus van de Poll et al. [12], the largest drop of performance occurred between STI values of 0.23 and 0.34. This could be an explanation of the absence of an improvement of performance in this experiment although in any case a significant improvement between the quiet and all other sound scenarios can be expected. ...
Previous research has shown that semantic-based tasks are negatively influenced by semantic aspects in background speech. Collaboration is an important task in open-plan study environments and is a semantic task which might be disrupted by background speech. Therefore, the aim of this study was to analyze the influence of irrelevant background speech on student-collaboration. Participants worked in pairs to solve spot-the-difference puzzles, by using the 'DiapixUK' collaboration task, while they were exposed to different background sound scenarios. The composed sound scenarios varied in semantic content (mother tongue and foreign language background speech)and reverberation time (short vs long), the latter affecting speech intelligibility. Although a longer reverberation time decreases the intelligibility of background speech and a foreign language decreases meaningfulness of speech, no significant changes in performance were found. On the other hand, the data show an increased perceived disturbance for a longer reverberation time, which we interpret as an increased difficulty of interpersonal communication in the collaboration task due to the increased level of the background speech. The quiet reference condition was the most preferred sound condition which is in line with both the effect of a low background sound level and the absence of semantic interference.
... Another interesting result in Haka et al. [14] is that subjective evaluation was disturbed more easily than performance. On their side, Jahncke et al. [15] used a serial-recall task of words. In their experiment, the STI varied from 0 to 0.7. ...
... The result of decrease in performance (DP) due to sound is shown in figure 2. The repeated ANOVA measure shows a highly significant effect of the STI on the decrease in performance (F (3) = 4.32 p = 0.0059). This effect confirms the other results found in the studies mentioned previously [12][13][14][15][16][17]. More precisely, decrease of performance is constant for the two highest STI values, confirming the plateau of the curve proposed by Hongisto (see figure 1). ...
It seems now accepted that speech noise in open plan offices is the main source of discomfort for employees. This work follows a series of studies conducted at INRS France and INSA Lyon based on Hongisto's theoretical model (2005) linking the Decrease in Performance (DP) and the Speech Transmission Index (STI). This model predicts that for STI values between 0.7 and 1, which means a speech signal close to 100% of intelligibility, the DP remains constant at about 7%. The experiment that we carried out aimed to gather more information about the relation between DP and STI, varying the STI value up to 0.9. Fifty-five subjects between 25-59 years old participated in the experiment. First, some psychological parameters were observed in order to better characterize the inter-subjects variability. Then, subjects performed a Working-Memory (WM) task in silence and in four different sound conditions (STI from 0.25 to 0.9). This task was customized by an initial measure of mnemonic span so that two different cognitive loads (low/high) were equally defined for each subject around their span value. Subjects also subjectively evaluated their mental load and discomfort at the end of each WM task, for each noise condition. Results show a significant effect of the STI on the DP, the mental load and the discomfort. Furthermore, a significant correlation was found between the age of subjects and their performance during the WM task. This result was confirmed by a cluster analysis that enabled us to separate the subjects on two different groups, one group of younger and more efficient subjects and one group of older and less efficient subjects. General results did not show any increase of DP for the highest STI values, so the "plateau" hypothesis of Hongisto's model cannot be rejected on the basis of this experiment.
... The results revealed simultaneous increases in privacy and communication after the move. This is an important finding, as privacy and communication are crucial to employee performance (Jahncke et al., 2013;Haapakangas et al., 2019) but have previously been considered incompatible (Kim and de Dear, 2013). We discuss these findings in more detail below. ...
Purpose
The aim of this study is to investigate whether activity-based workspaces (ABWs) are able to solve the privacy-communication trade-off known from fixed-desk offices. In fixed-desk offices, employees work in private or open-plan offices (or in combi-offices) with fixed workstations, which support either privacy or communication, respectively. However, both dimensions are essential to effective employee performance, which creates the dilemma known as the privacy-communication trade-off. In activity-based workspaces, flexible workstations and the availability of different spaces may solve this dilemma, but clear empirical evidence on the matter is unavailable.
Design/methodology/approach
To address this knowledge gap, the authors surveyed knowledge workers ( N = 363) at a medium-sized German company at three time points (T1–T3) over a one-year period during the company’s move from a fixed-desk combi-office (a combination of private and open-plan offices with fixed workplaces) to an ABW. Using a quantitative survey, the authors evaluated the employees’ perceived privacy and perceived communication in the old (T1) and the new work environments (T2 and T3).
Findings
The longitudinal study revealed a significant increase in employees’ perceived privacy and perceived communication in the ABW. These increases remained stable in the long term, which implies that ABWs have a lasting positive impact on employees.
Originality/value
As the privacy and communication dimensions were previously considered mutually exclusive in a single workplace, the results confirm that ABWs can balance privacy and communication, providing optimal conditions for enhanced employee performance.
... For example, cognitive performance decline due to background speech, noise masking techniques and restorative effects of water sounds have been broadly explored during open -plan offices' tasks and in rehabilitation settings (7,8,9,10). Personalized indoor acoustic spaces have been studied from the perspective of communication and privacy preferences (11). ...
Acoustic environments of office spaces influence workers' well-being and performance. This influence was investigated with ISO12913 guidelines for soundscape studies. Using a within-subject design, 29 participants, 18 to 54 years old (Mean = 33.62, SD = 10.86); 6 women and 23 men performed a Reading Span Task (RST) under three sound conditions: silence (E1), office environment (E2), and office environment mixed with oscillating sounds of nature (E3). The oscillatory frequency was set to each participant´s optimal breathing rate, i.e., Resonant Frequency Breathing Rate (RFBR). Perception of the sound conditions, RST scores, biological signals related to arousal, i.e., heart rate variability, skin conductance and temperature, personality traits and executive functions' deficits were assessed. Related sample t-test showed that E3 was perceived as more pleasant and calm than E2, and more vibrant and eventful than E1. Further, spearman's correlations showed a positive relation between the identification of sounds of nature, perception of E3 as calm, heart rate variability, working memory capacity and lower processing error in RST. Similarly, there is a positive correlation between the perception of E3 as vibrant and skin conductance levels. These findings suggest that oscillating sounds of nature facilitate optimal breathing, noise masking and attention, supporting the design of healthier and smarter working conditions.
... The first such norms were collected in the USA in 1957 (Cohen et al., "The Connecticut Norms"), and were subsequently updated by Battig and Montague (1969) in their widely cited set of norms. Since then, category production norms have been published in at least nine different languages (see Fig. 1), which have been used in a wide range of psychological research, including psycholinguistics (e.g., Stadthagen-Gonzalez et al., 2017;Warriner et al., 2013), memory (e.g., Ryan et al., 2008;Veling & van Knippenberg, 2004), language comprehension (e.g., Federmeier et al., 2010;Jahncke et al., 2013), cognitive ageing (e.g., Ferreira et al., 2019;Raz et al., 1998), and disorders such as schizophrenia (e.g., Brébian et al., 2010;Vinogradov et al., 1992) and Alzheimer's disease (McDowd et al., 2011;Ober et al., 1991). ...
We present a database of category production (aka semantic fluency) norms collected in the UK for 117 categories (67 concrete and 50 abstract). Participants verbally named as many category members as possible within 60 seconds, resulting in a large variety of over 2000 generated member concepts. The norms feature common measures of category production (production frequency, mean ordinal rank, first-rank frequency), as well as response times for all first-named category members, and typicality ratings collected from a separate participant sample. We provide two versions of the dataset: a referential version that groups together responses that relate to the same referent (e.g., hippo, hippopotamus) and a full version that retains all original responses to enable future lexical analysis. Correlational analyses with previous norms from the USA and UK demonstrate both consistencies and differences in English-language norms over time and between geographical regions. Further exploration of the norms reveals a number of structural and psycholinguistic differences between abstract and concrete categories. The data and analyses will be of use in the fields of cognitive psychology, neuropsychology, psycholinguistics, and cognitive modelling, and to any researchers interested in semantic category structure. All data, including original participant recordings, are available at https://osf.io/jgcu6/.
... Architectural acoustics is an important consideration in the overall comfort of openplan offices. Researchers [1][2][3][4][5][6][7] have made considerable effort to investigate the acoustics of open-office spaces and present potential solutions for improving their indoor environmental quality. Examples of these solutions are (1) configuring the floor plan to effectively balance and acoustically separate areas; (2) designing collaborative and transition spaces with sound-absorbing surfaces; (3) employing high-performance, noise-reducing interior partitions, and exterior facades; and (4) adding background noise control and enhancement measures for selective workstation. ...
The aesthetic and functional appeal of high-performance, open-plan office buildings presents special challenges. Extensive use of glass at the building’s perimeter to improve visual comfort and office communication can negatively impact acoustic comfort without proper design considerations. This study investigates the utility of a novel visualization approach to documenting the interactional impact of acoustical comfort on the health and well-being of occupants in an open-office environment. Room acoustic measurements of background noise and speech transmission index were conducted and distraction distances were calculated and visualized using a mapping technique. In addition, a comprehensive pre-and post-occupancy evaluation protocol was employed. The paper illustrates the reliability of the visualization approach to aid in the interpretation and comparison of various open-office acoustic solutions from a human-centric acoustic environment perspective.
Buildings:12(3), 338; https://doi.org/10.3390/buildings12030338
... In particular, the lack of sound privacy has been demonstrated to be a major acoustic factor negatively affecting the subjective overall workspace satisfaction of workers in OPOs [7,9]. Intelligible conversation among workers or irrelevant speech were determined to be the primary causes of decreased worker satisfaction and performance and increased mental workload in OPOs [10][11][12][13][14][15][16][17][18][19][20]. Therefore, the violation of privacy due to worker speech must be considered when designing the sound environment of an OPO to improve worker satisfaction. ...
To implement pleasant open plan offices (OPOs) in the preference aspect based on the subjective responses of the workers, we proposed novel acoustic environment design classification criteria for speech privacy-related parameters. To this end, we created acoustic stimuli through computer simulations and surveyed the related preference responses of test participants. Then, we selected classification criteria based on the survey response results. First, field measurements were performed in two typical OPOs, and a computer simulation model was built. Twelve different sound stimuli were generated by changing the material absorption coefficient conditions for the ceiling and floor inside an office. The investigation of the noise sensitivity and satisfaction of each sound source according to the individuals indicated that the A-weighted sound pressure level at 4 m (Lp,A,S,4m) and spatial decay rate of speech (D2,S) were the major acoustical parameters that determined OPO satisfaction, with Lp,A,S,4m considered first in the OPO design stage. The Lp,A,S,4m class interval was set to 2 dB, and a new four-level classification criteria was proposed, in which the participant response rates of satisfaction were divided according to the change of Lp,A,S,4m into 25% intervals: A (≤46 dB), B (46 dB ≤ ≤ 48 dB), C (48 dB ≤ ≤ 50 dB), and D (≥50 dB). A large difference of two or more satisfaction classes was observed between the high and low noise sensitivity groups for the same Lp,A,S,4m, confirming that the noise sensitivity of workers influences the preferences for OPOs. The proposed classification criteria are expected to be applicable to the design of comfortable OPOs in the future.
... It was found that low frequency or ventilation noise impairs demanding verbal tasks, 8,9 while irrelevant background speech in open-plan offices disrupts short-term memory and information searching tasks. 10,11 Moreover, Jahncke et al., 12 in a study on the cognitive, emotional and physiological effects of two open-plan office noise conditions, found that participants felt more tired and less motivated after working for 2 h in high noise, compared to low noise conditions. Noise exposure during early learning at school impairs individual development and have a lifelong effect on educational attainment. ...
Previous evidence has shown that exposure to urban noise negatively influences some cognitive abilities (i.e. verbal fluency and delayed recall of prose memory) of people in indoor spaces. However, long-standing literature in the cognitive domain has reported that men and women can show different performance on cognitive tasks. Here, we aimed to investigate if and how different patterns of perceived urban noises in indoor environments could affect male and female participants’ cognitive abilities. Ambisonic sound recordings representing scenarios with varying noise patterns (low, medium and high variability) were acquired with an open window at three dwellings in a southern Italian city. As a control condition, the recordings were caught inside a quiet room. While exposed to theses four auditory conditions, participants had to perform cognitive tasks assessing free verbal memory recall, auditory–verbal recognition and working memory. The results show that male and female participants have a different tolerance to noise patterns. Women overperform men on verbal tasks, while the contrary effect emerges with men outperforming women on visuospatial working memory tasks.
... The study from 2009 is the smallest sample of offices in Fig. 9 but has been cited in many recent studies to represent typical L A, eq values in offices (e.g., [39]). This study provides most of the relevant physical details about the sampled offices, the sound environment, with the measurements lasting a working day (7 h). ...
Open-plan offices (OPOs) have been around for more than half a century now, chronicling the vicissitudes of workplace topography amongst other factors. This paper addresses one such factor – the sound environment in occupied OPOs in relation to several objective workplace parameters, using measurements in contemporary OPOs and comparisons with studies over the last 50 years. Omnidirectional and binaural sound measurements were conducted in 43 offices during typical working hours. The results describe variation in several acoustic and psychoacoustic metrics, and present statistical models that predict these metrics as a function of the number of workstations in offices. LA,eq of 53.6 dB is typical for occupied OPOs, with spectral slope of approximately −4 dB/octave. LA,eq values do not vary much over the workplace parameters studied (e.g., floor plate area, work activity, etc), except for −2.7 dB and −4.1 dB differences between offices with/without carpeting, and offices with ceiling absorption but with/without carpeting, respectively; most likely from reduced floor impact noise leading to speech level reduction. Sound fluctuation, as characterised by the metric Noise Climate (NCl: LA10 – LA90) and the psychoacoustic Fluctuation Strength (FS), decreases significantly with increasing number of workstations in OPOs. This suggests lesser auditory distraction in larger offices, which needs further investigation. In terms of historical trends, OPOs have become quieter over the years, especially background noise quantified as LA90, although there are several subtleties. Overall, current findings can inform several OPO design perspectives including policy documents, provide values for laboratory simulations of OPO acoustic environments, help interpret subjective impressions of OPO occupants, etc.
... This instrument has not been validated but was developed by the researcher Helena Jahncke to further understand the content of work tasks related to office design. The instrument is based on results from laboratory studies, identifying work tasks and processes affected by noise in open landscape offices [33,34]. ...
Studies using technical measurements of physical behavior show wide interindividual variations. This study aimed to explore underlying factors related to sitting, standing and walking among office workers. Cross-sectional data for background characteristics, work-related variables, and device-based measures for sitting, standing and walking were collected among office workers in either a cell office or a flex office with activity-based work. Data were analyzed by Factor Analysis of Mixed Data (FAMD) and multiple robust linear regression. The FAMD resulted in the combination of underlying factors describing six character types. The (1) harmonic and healthy, (2) disabled with poor health, (3) manager that spend a lot of time in meetings and has very high workload, (4) engaged with high workload, (5) employee with creative and computer intense work, with high workload and, (6) employee with high BMI with creative and collaborative work. Regression analysis showed that the character type that was “engaged with high workload” sat more and stood less, while the character type with ”high BMI and with creative and collaborative work” sat less. The results suggest that physical behavior among office workers is influenced by a complex combination of factors, which should be taken into account in the evaluation of future studies of larger cohorts.
... Office tasks may, however, require that employees keep pieces of information in memory, for example during identification and booking of train journeys, where rehearsal of digits in the right order is a central process to keep them memorized (Perham, Banbury, & Jones, 2007). Moreover, other studies testing the effects of background speech on different work tasks have found similar reductions in performance on tasks that for instance require memory, information search, arithmetics and writing (Jahncke, 2012b;Jahncke, Hongisto, & Virjonen, 2013;Keus van de Poll et al., 2014). ...
Distraction from the background environment while performing concentrationdemanding tasks is a common issue for office employees in shared work areas. However, few field studies have been conducted on the effects of different office types and work areas on objective measurements of cognitive performance. The first aim of the present field study was to investigate, before relocation to an activity-based workplace (ABW), differences in performance on a concentration-demanding cognitive task between individuals in shared/open-plan offices compared to cell offices. The second aim was to investigate, after relocation, how performance differs (withinperson) between different work areas within the ABW. This study included employees from five offices (n = 113), of which four relocated into an ABW. An acoustician measured the equivalent sound levels of the work areas. Data were analyzed using linear regression (aim 1) and mixed models (aim 2). Before relocation, employees working in shared/open-plan offices performed significantly worse (14%) than those in cell-offices, which had a 15 LAeq lower noise level. After relocation, employees performed significantly worse in the active zone without noise restrictions, compared to all other work areas. When shifting open-plan area from the active zone to the quiet zone cognitive performance increased significantly by 16.9%, and switching to individual working rooms increased performance by 21.9%. The results clearly demonstrate the importance for organizations to provide quiet areas or rooms with few distractions for employees working on tasks that demand concentration in an ABW. A daily drop in performance for each employee may be expensive for the organization in the long run.
... Current international standard for the measurement of room acoustic parameters in open-plan offices is formulated with reference to the results of open-plan offices in Finnish environment [4,30,34]. However, the study in Swedish environment (at SNRs = À33, À11.1, À7, À4.3, À0.2 and 17.8 dB) showed that occupants' overall performances are not significantly different within SNR = À33 to À11.1 dB, while their performances begin to decrease at SNR = À7 dB and reach a minimum at SNR = À0.2 dB [35]. The study in German environment (at SNR = À12, À9, À6, À3 dB) showed that serial recall scores are not significantly different within SNR = À12 to À9 dB, while the scores begin to decrease at SNR = À6 dB and reach a minimum at SNR = À3 dB [23]. ...
A laboratory experiment has been carried out in this paper to study the effects of masking sound and signal-to-noise ratio (SNR) on occupants’ objective performance and perceived sound environmental quality in Chinese open-plan offices. The serial recall task performance and subject perceptions of 30 participants were tested under 14 different acoustic conditions, including “Quiet” (the condition without neither masking sound nor speech noise), “Speech_only” (the condition without masking sound but with speech noise), and 12 masking sound conditions. In these masking sound conditions, 4 masking sources (speech-like pink noise, air-conditioning noise, spring water sound and babble) were used and each source was given under 3 levels of SNR (i.e., small (−6.6 to −5.5 dB), medium (−3.0 to −2.3 dB) and large (4.4–4.8 dB) levels). The results demonstrate: (1) the effects of masking sound environment on occupants’ objective performance and perceived sound environmental quality (including acoustic satisfaction, perceived disturbance and subjective workload) can significantly differ by masking source and SNR, (2) spring water sound at medium SNR (SNR = −2.4 dB) is the best condition among the tested 12 masking sound environments, and (3) the effects of masking sound on occupants may differ by their individual factors, such as gender, educational level and noise sensitivity. According to the authors’ knowledge, this study is the first attempt to study the effects of masking sound and SNR on work performance in Chinese-language open-plan office environments. The findings can be used as a reference for the acoustic research and design of Chinese open-plan offices.
... Kim and de Dear, 2013, p. 23). Concerning privacy, in a study of Jahncke et al. (2013), a noisy room resulted in a 6% productivity decrease specifi cally for employees whose work involves the processing of new information. Concerning ergonomic comfort, in a study of Robertson (2007), improving an offi ce space with among others ergonomically designed workstations resulted in a 5,5% productivity increase. ...
The current usage of natural resources cannot be maintained forever – our resources are depleting. A substantial share of resource usage, and therefore the problem, is related to the construction sector. Meanwhile, there are signs that buildings are being demolished prematurely. This premature demolition of buildings is a waste of resources. This dissertation’s end goal is to contribute towards mitigating the problem of resource depletion. Changeability has been selected as the means through which to pursue this goal. This research aims to both understand design and to create support to help improve design, specifically regarding the topic of design for change in relation to sustainable resource usage.
In Chapter 2, i.e. “Resource depletion, where is an intervention most effective?”, the topic of resource depletion is dealt with. Chapter 2’s aim is to rank areas of the resource system, according to how much of an impact can be expected from interventions in the area, in relation to the problem of depleting resources. Firstly, principles of Structured Analysis are used to model the process of resource usage, and, from this model, five intervention areas are defined. Secondly, these intervention areas are ranked in terms of effectiveness, through the use of Analytic Hierarchy Process. To be most effective, one must prioritize intervention areas as follows: (1) material inputs to the operation phase; (2a) process inputs to the operation phase and (2b) products’ longevity; (4) process inputs to the manufacturing phase; and (5) material inputs to the manufacturing phase. In this study, changeability is not pursued for the sake of changeability. Changeability is pursued for the sake of mitigating the problem of resource depletion. Chapter 2’s outcome can guide this pursuit of changeability in the right direction.
In Chapter 3, i.e. “The evolution of ordinary houses, does it justify demolition?”, the topic of longevity in relation to change is dealt with. Chapter 3’s aim is to determine how the ordinary house, in the Netherlands, has changed throughout the last 100 years. This information is then used to discuss: to what extent the house’s evolution justifies demolition. A non-random sampling method is used to select 68 housing projects from the city of Nijmegen. These projects contain a total of 8270 housing units (≈10% of Nijmegen’s housing stock). Of each project, a standard housing unit is analysed in terms of: (1) length and width; (2) floor-to-ceiling height; (3) utilitarian rooms; (4) spatial layout; (5) type of structure; (6) roof structure; (7) insulation; and (8) separating wall’s thickness. Chapter 3’s outcome provides a first indication of to what extent a building’s longevity is determined by its design. This knowledge contributes to a more valid assessment of changeability’s contribution towards mitigating the problem of resource depletion.
In Chapter 4, i.e. “How to set up criteria for evaluating a building’s changeability?”, the topic of changeability is dealt with. In Chapter 4, a method is proposed in which: (1) scenarios are developed to identify potential problems; and (2) evaluation criteria are based on design solutions to those potential problems. To support and guide the development of both scenarios and design solutions, changeability levels and types of design tactics are defined. A top-down approach is used to define changeability levels, while a bottom-up approach, i.e. the constant comparative method, is used to define types of design tactics. This research’s main contribution is that it provides a method for unpacking the black box of design for change. This method is presented in Chapter 4.
In Chapter 5, i.e. “How adjustable is the Environmental Building?”, the application of the evaluation method, that has been presented in Chapter 4, is tested. To do so, the Environmental Building’s adjustability is evaluated by following the steps described in this method. Adjustability is the first of four changeability levels, as defined in Chapter 4. The Environmental Building has the ability to comply with changing requirements of the individual in terms of indoor climate conditions. However, it lacks the ability to comply with changing requirements of the individual in terms of space, privacy and interaction. Chapter 5 demonstrates that by using this method, specific strengths and weaknesses of the building’s design can be identified.
... words) in a noisy surrounding compared to a low noise environment which can also negatively impact their motivation to work [24]. An investigation on cognitive performance impairment caused by irrelevant background speech with varying degrees in open-plan office has been conducted by [25], which found that a strong relationship between speech intelligibility and the cognitive performance of workers. The research also identified that several officetasks are more prone to distraction than others. ...
One of the core challenges in open-plan workspaces is to ensure a good level of concentration for the workers while performing their tasks. Hence, being able to infer concentration levels of workers will allow building designers, managers, and workers to estimate what effect different open-plan layouts will have and to find an optimal one. In this research, we present an ambient-physical system to investigate the concentration inference problem. Specifically, we deploy a series of pervasive sensors to capture various ambient and physical signals related to perceived concentration at work. The practicality of our system has been tested on two large open-plan workplaces with different designs and layouts. The empirical results highlight promising applications of pervasive sensing in occupational concentration inference, which can be adopted to enhance the capabilities of modern workplaces.
... words) in a noisy surrounding compared to a low noise environment which can also negatively impact their motivation to work [24]. An investigation on cognitive performance impairment caused by irrelevant background speech with varying degrees in open-plan office has been conducted by [25], which found that a strong relationship between speech intelligibility and the cognitive performance of workers. The research also identified that several officetasks are more prone to distraction than others. ...
One of the core challenges in open-plan workspaces is to ensure a good level of concentration for the workers while performing their tasks. Hence, being able to infer concentration levels of workers will allow building designers, managers, and workers to estimate what effect different open-plan layouts will have and to find an optimal one. In this research, we present an ambient-physical system to investigate the concentration inference problem. Specifically, we deploy a series of pervasive sensors to capture various ambient and physical signals related to perceived concentration at work. The practicality of our system has been tested on two large open-plan workplaces with different designs and layouts. The empirical results highlight promising applications of pervasive sensing in occupational concentration inference, which can be adopted to enhance the capabilities of modern workplaces.
... Research has shown that the sound pressure level of normal-effort speech at a neighboring workstation varies between an L Aeq 39 and 55 dB. 9,14,35,36 The speech signals in the current study were calibrated to have a sound pressure level of L Aeq,7s of 48 dB. Above this speech level, a masking sound would need to be too loud to effectively mask speech, and speech levels significantly below this (e.g., 39 dBA) would likely be too quiet to require a masking system. ...
This paper examines the use of water features for masking irrelevant speech and improving the soundscape of open-plan offices. Two laboratory experiments were carried out, as well as acoustic simulations and field tests. Experiment 1 aimed to identify the preferred sound level of water sounds against irrelevant speech. Experiment 2 examined the audio-only and audio-visual preferences and perception of waterscapes. Acoustic simulations and field tests examined the impact of design factors. The results showed that, when played against a constant level of irrelevant speech of 48 dBA, people prefer to listen to water sounds of 42–48 dBA (45 dBA being best). These results and results from previous research suggest that water sounds work mainly as informational maskers rather than energetic maskers. Furthermore, the introduction of a water feature improved the perception of the sound environment, and adding visual stimuli improved perception by up to 2.5 times. Acoustic simulations indicated that features at each corner and one at the center (or a single feature with an array of speakers) can provide appropriate masking for a large open-plan office, whilst field tests showed that water sounds decrease the distraction and privacy distances significantly (clusters of workstations benefitting more than rows of workstations).
... P (STI ＝0.2)的确定依据. 后续研究发现, 认知任务 [74] 以及语 种 [75] 不同, 曲线的形状和性能下降的幅度有所不同. ...
... Future research can also be extended to gain greater insight into the effect of babble noise on performance, as seen in the present research. Moreover, babble noise (speech sound) is thought to induce effort, to extract meaning from the sound, even if it is meaningless [14,20]. Whether the noise effect evident in the present research was due to the additional cognitive load imposed by the babble noise remains unknown. ...
Learned helplessness results when individuals learn that their behaviour is independent of a situation and this learning affects future behaviour. Whether noise present in workspaces related to transportation, such as the check-in counter at an airport or in the aircraft cabin can induce learned helplessness was examined. In both these workplaces, the personnel undertake important tasks, but have no control over the noise around them. Participants (university students) were randomly divided into three conditions (Control, Escape, Inescapable), half were exposed to noise typical of that present in the check-in area for an airport (i.e., babble) and the other half to noise typical of that in an aircraft cabin (i.e., broadband). Both babble and broadband noise were shown to induce learned helplessness (i.e., affects motivation). The results also revealed that exposure to babble noise, when escape from the noise was possible, adversely affected performance during the test condition, while broadband noise did not. The findings highlight that while there is a difference in performance with noise type, both types of noises can induce learned helplessness.
... For example, employees completing complex and concentration-demanding tasks tend to report higher stress and distraction in shared workplaces (Fried et al., 2001;Seddigh et al., 2014), suggesting that this type of work is more effectively completed in segregated spaces. Similarly, tasks which require the processing of verbal/numerical (rather than visual/spatial) information are particularly susceptible to disruption by the presence of background speech (Haka et al., 2009;Jahncke et al., 2013), so employees completing this type of work may also be less suited to open office environments. Finally, typical interaction levels with colleagues may also be important. ...
Purpose: To identify the employee characteristics which are most strongly associated with perceived requirements for different aspects of the workplace environment.
Design/Methodology/Approach: A questionnaire was completed by 364 employees from a large private-sector organisation. Respondents were surveyed on different work-related, personality, and demographic characteristics. They then completed a series of items measuring perceived requirements for four aspects of the workplace environment (workspace segregation, workspace territoriality, individual environmental control, and aesthetic quality). Associations between employee characteristics and perceived workplace requirements were explored using multiple regression analyses.
Findings: Numerous significant associations emerged. For example, the requirement for more segregated workspaces was associated with higher susceptibility to distraction, and the requirement for higher workspace territoriality was associated with less positive perceptions regarding the impact of flexible working on work effectiveness.
Originality/Value: The individual difference factors which moderate satisfaction with the workplace environment have received relatively little attention in past research. The present study addresses this knowledge gap by including a wider range of employee characteristics and comprehensively investigating which of these most strongly predict differences in perceived requirements for the workplace.
... The speech transmission index (STI), which is a metric to predict the speech intelligibility, is suggested to predict both subjective noise disturbance and work performance (5,(11)(12)(13)(14). According to a model that predicts the effect of the STI on the performance of cognitively demanding tasks, concentration and privacy start to improve at STI values below 0.50 (11,15). ...
Speech privacy is one of the most crucial, yet least satisfying aspects in open-plan offices. Background speech often causes high distraction and dissatisfaction. At medium to large distances speech intelligibility should be minimised to reduce the disturbing impact whereas at short distances intelligibility may remain high to support communication within teams. A holistic acoustical design takes the requirements of the occupants into consideration. Besides the zoning of teams and the application of an appropriate layout, the combined use of sound absorbers, screens and masking can diminish the impact of disturbing speech at medium to large distances. The height of the used screens can have a high impact on the spatial decay of sound pressure level and on the resulting speech privacy at medium distances. As part of this study sound pressure level measurements of 23 offices are clustered into three groups, namely ‘no screens’, ‘half-high screens’, and ‘room-high screens’. The level differences at medium distances of 5–10 m are significantly different: whilst ‘no screens’ and ‘half-high screens’ result in level differences of 15–20 dB, ‘room-high screens’ yield level differences of 25–35 dB. This implies that only ‘room-high screens’ can reduce the disturbance by background speech at medium distances sufficiently.
... Employees subjectively perceive office noise and background speech as being disturbing [e.g., [9][10][11][12][13]. And besides that subjective feeling, office noise demonstrably reduces cognitive performance, especially if it consists of background speech [e.g., [14][15][16][17]. ...
Office noise has been shown to impair cognitive performance and subjective evaluations in a multitude of studies. To reduce such disturbance effects, continuous noise is played in many open-plan offices as a partial masker. Yet, whether another sound, such as music or nature sounds, can be used instead is questionable and could not be unequivocally answered in extant studies [1, 2, 3]. The reported experiments investigated whether the beneficial performance effects of continuous noise and the positive preference ratings of instrumental music reported by Schlitt-meier and Hellbrück [3] can be unified into one partial masker by combining these two sounds. In Experiment 1, short-term memory performance (n = 40) was tested during silence, office noise and three masking conditions in which a combined masker, continuous noise or music was superimposed on office noise. In Experiment 2, subjective evaluations were collected from students (n = 72) who did academic homework for 1 h during one of the three masking conditions of Experiment 1. In sum, performance data and subject ratings underline the potential of a composite masker (continuous noise plus instrumental music) for office environments.
... The lyrics of background song is very similar with background speech, which can greatly reduce cognitive performance and increase workload (Liebl, Assfalg, & Schlittmeier, 2016;. Besides, it causes more distraction if the primary tasks require semantic processing (Jahncke, Hongisto, & Virjonen, 2013), such as reading tasks used in this study. The melody part usually affect listeners' emotion, and that effect depended on the music genre (Balogun et al., 2013;Kämpfe et al., 2011). ...
Multisensory learning has the potential to facilitate learning outcome. However, visual, auditory, and tactile information can be distractive under certain circumstance, and the effect of their combination has not been fully explored. In two experiments, sixty-four participants read Chinese paragraphs and then answered multiple-choice questions with visual, auditory, and tactile distractions, and their combinations. Distractions were discrete in experiment 1 and continuous in experiment 2. Auditory distraction (deviant sounds and music) increased workload most and slowed down reading speed. Tactile distraction also increased workload, but combing tactile distraction with auditory distractions did not further increase the workload. Although visual distraction alone did not affect workload, combining it with auditory and tactile distractions further increased the workload. Auditory distraction affects reading the most, so we should avoid or mask irrelevant sounds in the learning environment. Multisensory learning protocols should be tested before being put into practice.
... Lack of privacy is a stress factor associated with decreased work ability and well-being (Herbig, Schneider, & Nowak, 2016). Office environments with low privacy tend to involve acoustic distractions (Sundstrom, Burt, & Kamp, 1980), such as other people's conversations Pierrette, Parizet, Chevret, & Chatillon, 2015) which impair performance in many cognitive tasks (Haapakangas, Hongisto, Hyönä, Kokko, & Keränen, 2014;Jahncke, Hongisto, & Virjonen, 2013;Keus van de Poll, Ljung, Odelius, & Sörqvist, 2014). Such acoustic problems also increase perceived task demands (Haapakangas et al., 2011;Keus van de Poll et al., 2015). ...
When organizations adopt activity-based workplaces (ABWs), improved interaction is a common goal. Yet, few controlled longitudinal studies have been conducted on the effects of ABWs on interaction, social relations and work demands. The aim of this natural intervention study was to investigate the effects of moving into an ABW on satisfaction with communication, on social relations (i.e., social support and social community) and on work demands (i.e., quantitative demands, emotional demands and work pace) 3 months and 12 months after the relocation. The study included four offices which relocated into an ABW and one control office that did not. Questionnaire data from 408 respondents were analyzed with linear mixed models. Satisfaction with communication and the sense of belonging to a community had decreased 3 and 12 months after the relocation. Work pace was not affected while small, mostly short-term, negative effects on social support, quantitative demands and emotional demands were only observed among employees who had moved to ABWs from private offices. Differences between office sites were also observed. The results suggest that, to avoid negative outcomes, organizations moving to ABWs should focus on solving difficulties in locating colleagues at the office and on supporting particularly workers from private offices in adopting activity-based working.
... The findings reported that almost half of the respondents perceived to be productive in the workplace. Work roles and needs impacted the requirement for disruption-free environments for deep thinking and longer periods of concentration, as noted in previous studies (Haynes et al., 2017;Babapour et al., 2018;Rolfö et al., 2018;Jahncke et al., 2013;Hoendervanger et al., 2018). Amplified interactions and knowledge sharing in the open workplace environment increased perceived productivity for some workers. ...
Purpose
Corporations balancing real estate holding (CRE) costs with recruitment-retention increasingly use activity-based flexible offices (AFO) to right-size environments for a mobile workforce. In this layout, workers have the option to select between a mix of unassigned workstations and alternative work settings (AWS) that support autonomy and mobility. The open layout encourages visibility and access to colleagues to enhance communication and collaboration. Nevertheless, studies into the effects of AFO environment attribute effects on worker needs and work outcome are sparse. Therefore, this study aims to focus on understanding how environmental features and psychological or job needs impact observed and perceived satisfaction, communication, collaboration and perceived productivity.
Design/methodology/approach
Data were collected in a case organization piloting an AFO before implementation across their CRE portfolio. A mixed-methods approach was used, including systematic observations, space syntax and surveys collecting information on the observed and perceived satisfaction, communication, collaboration and productivity.
Findings
Collaboration instances were higher in AWS, especially more visible and accessible open areas, supporting higher impromptu interactions and enhanced perceptions of productivity of team members and cross-team members. Privacy requirements linked to a greater demand for enclosed AWS. Team communication satisfaction depended on how easily teams were located. Almost half of the user teams clustered within workstation zones corresponding to territoriality needs. Job autonomy satisfaction depended on the availability of preferred workstation or AWS, enabling private, uninterrupted work that enhanced perceived productivity.
Practical implications
The case study findings indicated a correlation between the AFO environment and worker needs impacting workplace satisfaction, communication, collaboration and perceived productivity.
Originality/value
The findings form this case study indicated that a fit between the AFO environment and needs impacted workplace satisfaction, communication, collaboration and perceived productivity.
... Research on negative influences of noise in the work environment on employees' well-being and performance is extensive (Jahncke et al., 2012(Jahncke et al., , 2013Kaarlela-Tuomaala et al., 2009;Seddigh et al., 2015). Nevertheless, research in the field of facility management addresses health and well-being in relation to buildings from a broader perspective (Clements-Croome, 2018), and stresses the relevance that spatial attributes have for occupants' health, wellbeing and performance (Barrett, 2018). ...
Purpose – This paper aims to investigate employee well-being in relation to office landscapes in a post-relocation context. The aims are to identify spatial attributes of the office landscape that influence employee well-being and underlying contextual factors that explain employee well-being post-relocation.
Design/methodology/approach – A mixed-method approach was adopted. The data collection involved 16 semi-structured interviews with employees, an interview with the leading architect of the office renovation, study of a dossier on the renovation project and observations.
Findings – Most of the informants experienced the new office landscape positively despite few shortcomings. Spatial attributes were identified that influenced the informants’ well-being positively in terms of affects, satisfaction, social relations and environmental mastery. Conversely, negative influences on wellbeing were also reported regarding affects, satisfaction and environmental mastery. Conflicting views on
some of the spatial attributes and contextual factors related to the planning process and the former office landscape were identified.
Originality/value – The value of this paper lies in investigating the office landscape at the spatial attributes level, despite office type, and their influence on hedonic and eudaimonic components of employee well-being. The research approach adopted proved its usefulness for in-depth studies of the interrelations between office landscapes and employee well-being.
Keywords Qualitative study, Well-being, Workspace design, Work environment, Office landscape,
Spatial attributes
Paper type Research paper
... Open office spaces, which are also characteristic for ABWs, decrease perceived privacy [20,21] and expose workers to different distractions, particularly coworkers' speech [22][23][24]. Lack of privacy is associated with lower environmental satisfaction [25,26] and stress symptoms [21,22,27], whereas irrelevant background speech has been shown to impair cognitive performance [28][29][30][31]. Thus, distractions can even be considered as an indirect indicator of decreased productivity [4]. ...
Activity-based offices are increasingly popular. However, productivity and well-being in these work environments have been little researched. The aims of this study were to quantitatively determine perception and use of the activity-based office environment in relation to self-rated productivity and well-being at work, and to identify important predictors of these outcomes. Four activity-based offices (N=239) in a large Swedish government agency were surveyed 12 months after implementation. Linear regression models adjusted for relevant covariates were constructed separately for the predictors satisfaction with the physical environment, privacy, communication, personalization, personal storage, IT functions and cleaning, as well as for the number of daily workspace switches, different workspaces used and the time spent looking for a workspace. Satisfaction with the physical environment, privacy and communication had the strongest positive associations with both self-rated productivity and well-being at work. Increased workspace switching was associated with higher productivity, while an increase in the self-reported time spent searching for a workspace was associated with lower productivity and well-being. However, predictors related to office use generally explained only a small proportion of variance in the two outcomes. The results suggest that office developers should focus particularly on privacy needs but also on communication, personalization, smooth workspace switching and minimization of work time spent looking for available workspaces.
... Several studies showed that objective measurements are related to working performance. [2][3][4] In an open-plan office, the furniture, the background noise level, and the distance between the speaker and the listener influence a Speech Transmission Index ( ) STI variation. The acoustic measurements must be done along a line of receiver positions. ...
Acoustic comfort in open-plan offices is a relatively recent research topic and some practices have not yet been consolidated. The goal in these spaces is to achieve good speech privacy at every workstation, reaching a high value of spatial decay of the sound pressure level. In case of refurbishment, a proper measurement of intelligibility criteria is needed, for example, in order to properly calibrate a numerical model or to plan acoustic treatments. This work compares different measurement techniques to evaluate the spatial distribution of intelligibility criteria. In situ measurements were done in an open-plan office used as a case study. Both omnidirectional and directional sound sources with different sound power levels were used, according, respectively, to ISO 3382-3:2012 and ITU-T P.51:1996. Furthermore, compensation algorithms were used in impulse response measurements in presence of Heating, Ventilation and Air Conditioning noise. The study shows, in a preliminary way, how different techniques and equipment can influence intelligibility criteria used in the open-plan office characterization. Results show that the indirect method of measuring Speech Transmission Index could not be used when the background level is high as the case study while the direct method returns good results.
... Schneider et al. 2000;Enmarker 2004;Larsby et al. 2005), the babble employed in this research contained no discernible speech. It is considered that the discernible speech is most disruptive cognitively, as individuals attempt to make sense of the speech in noise while also attending to the target stimuli (Venetoki et al. 2006;Jahncke et al. 2013). Hence, future research could compare the effects of babble, intelligible speech, with different levels of discernible speech on performance. ...
The comparative effects on both working memory and recognition memory of the same A-weighted noise levels of background noise, typically of that present in many transportation work areas, were investigated (55 and 65 dBA). One noise was a babble, multi-talker incomprehensible speech and representative of the many work areas dealing with administrative tasks. The other noise was broadband and similar to services and machinery noise. Forty participants, half non-native English speakers, were asked to complete three different working memory tests (linguistics, grammatical reasoning and mathematics) and one recognition memory test (cued recall) in the presence of the two types of noise at the two different levels. Broadband noise at 65 dBA was found to adversely affect recall by as much as 15%. The native language advantage was only evident with the linguistic working memory task. The findings highlight the interplay between type of noise, level of noise, demand of task, and language background of the person completing the task, and also the limitations of the use of dBA alone for assessment of acceptability of a workspace.
The use of virtual reality (VR) to study the effect of the acoustic environment on performance is still in its infancy, despite its many potentialities due to audio-visual improvement. In this study, a binaural soundtrack was generated and integrated within an immersive virtual environment of an office room, to evaluate the effects of an acoustic ambient on users’ cognitive performance and subjective evaluation. To generate the soundtrack, five disrupting sound sources (phone rings, machine noise, mechanical systems, human-based sounds and acoustical effects) were selected. 104 participants performed three productivity tests (working memory, inhibition, task switching) and answered questionnaires under a constant indoor air temperature (24 ℃). In particular, an independent measure experimental design was conducted: each group (52 subjects) randomly performed one test session: a no-ambient-noise condition or «quiet environment» was compared to a treated-with-noise condition, or «noisy environment» virtual session. The authors focused on two goals: verifying the external-ecological validity of the virtual model created and evaluating the effect of the sound stimuli on productivity. Findings revealed that the virtual office created an excellent level of presence and immersivity and confirmed, as expected, that work efficiency was negatively influenced by the ambient noise. A decrease in performance was detected in each cognitive test, as the subject evaluated the sound environment to be uncomfortable, chaotic and boring. Hence, the results supported the potentialities of the proposed acoustic virtual reality to study productivity in combination with different stimuli and layouts.KeywordsImmersive virtual environmentBinaural soundtrackWork efficiency
ATC (Air Traffic Control) is considered one of the most demanding jobs. This profession is considered a job with high mental workload due to its high-stress level and great responsibility. This study designed a suitable work system to improve operator performance by measuring the mental workload and the physical environment using the NASA-TLX method and safety concept by considering variables affecting the operator’s performance. This study also searched for the impact of mental workload on the work environment, the mental workload on performance, and the work environment on performance. Questionnaires were distributed to operators, and validation and verification tests were carried out using SPSS. At the PLS method's processing stage, the variables used in this study consisted of the dependent (Y) and independent (X) variables. The dependent variables in this study were performance and the physical environment of work of the operator. Meanwhile, the independent variable was mental workload. Based on the mental load calculation, an average WWL (weighted workload) score of 80 to 90 was obtained, and the factors affecting mental workload are performance aspects and mental demand. Based on the results of structural modelling with the PLS method, there was a significant influence between mental workload on the work environment, the mental workload on performance and the work environment on operator performance. The proposed work system design used an ergonomic approach, safety and regulation of Ministry of Health to get an ergonomic work system, regulate the equal distribution of workloads, create a safe and comfortable working environment, and improve operator performance. The design focused on the ATC tower's workstations and work environments. Supervisor has accepted the design.
Previously unpublished data from over 600 office buildings in the Center for the Built Environment (CBE) Occupant Survey database are used to perform a systematic analysis of dissatisfaction in contemporary workspaces. A total of 81% of respondents expressed dissatisfaction with at least one aspect of their workspace, and 67% with more than one. Acoustics were the most common source of dissatisfaction, particularly related to people talking, speech privacy, and phones. Other challenges included a perceived lack of control over the temperature and insufficient space, along with other associated problems of densely populated offices. The analysis shows that context matters when understanding occupant dissatisfaction. Occupants of open-plan offices with low or no partitions were almost twice as likely to complain about their workspace than someone in a private, enclosed office. Being near a window decreased the likelihood of dissatisfaction compared with those who were not near a window. There was a clear relationship between self-perceived performance and satisfaction with the indoor environment. Dissatisfaction profiles found that acoustics, space, and privacy-related items co-occur for many occupants dissatisfied with more than one workspace aspect.
Practical relevance
Post-occupancy surveys are a useful tool for evaluating whether an office environment supports occupants while conducting their work. While highlighting the successes is important, complaints from dissatisfied occupants can identify issues and pinpoint reasons why spaces do not meet expectations. The reported challenges generally relate to the simultaneous reduction in control and personalization with increasingly open and densely populated layouts. Occupant dissatisfaction may impact performance given the reported relationship between satisfaction with the environment and feeling supported by the workspace to complete work tasks. The themes emerging from this analysis identify common dissatisfaction sources that can serve as an empirical basis to identify common problems in contemporary workspace designs.
Keywords: dissatisfaction, indoor environmental quality, occupants, offices, open plan, post-occupancy evaluation, privacy, satisfaction, workplace, workspace design
How to Cite: Parkinson, T., Schiavon, S., Kim, J., & Betti, G. (2023). Common sources of occupant dissatisfaction with workspace environments in 600 office buildings. Buildings and Cities, 4(1), 17–35. DOI: http://doi.org/10.5334/bc.274
Open-plan offices (OPOs) are being increasingly implemented to promote communication and collaboration among coworkers. We investigated the effects of indoor soundscape perception on productivity and preferences for the work environment in OPOs containing various audiovisual contents to achieve high work-related quality. A subjective evaluation was performed through two experiments conducted in a virtual reality environment with various stimuli. In Experiment 1, we investigated the correlations of visual complexity and acoustical variability with work-related quality. The results on a seven-point Likert-like scale (−3 to 3) indicated that visual complexity and maximum appropriate acoustical variability of an OPO was recommended at −1.3–−0.2 and −0.3, respectively. In Experiment 2, the participants identified various noise sources and responded on their effects on the perceived affective quality and work-related quality. The results revealed that indoor soundscape perception can be interpreted in a comfort–content dimension and is significantly influenced by worker interactions such as conversation and laughter. Increased comfort improved the work environment preferences, and increased content significantly influenced the perceived productivity. Considering the factor score of the comfort–content dimensions, these results suggest the need to design a balanced OPO sound environment with preferred and productive zones by ensuring comfort and content distributions in the ranges of 0.3–0.7 and 0.6–1.2, respectively. The need to achieve an appropriate level of content in the indoor soundscape is confirmed, contradicting the notion that OPOs should be quiet. Therefore, these results can guide the design of sound environments in open office spaces.
The acoustic environment in the office space is a significant factor affecting workers' performance. Whereas existing research focuses mainly on the impact of the acoustic environment on single visual cognitive work performance, this study considers multitask visual cognitive work. Forty-one respondents were selected to participate in the multitask visual cognitive–behavioural cognitive experiment under different acoustic environments. The effects of different typical sound source types, sound pressure levels, and reverberation times on the performance of multitask visual cognition in design offices were examined. The results revealed the following. First, the sound source types have a significant impact on the reaction time of participants' work performance. Compared to the ambient environment (mean = 2.838 s), the reaction time performance is shortest under music sound (mean = 2.560 s). Second, the increase in traffic noise and air-conditioning noise will significantly reduce the memory accuracy of the location. For instance, when the traffic noise increases from 50 dBA to 65 dBA, the memory accuracy of the location is reduced by 4.42%. Third, the increase in the reverberation of speech will effectively shorten the reaction time and increase the memory accuracy of graphics. As the reverberation time of speech increases from 0.3 s to 1.5 s, the reaction time is reduced by 0.274 s. Meanwhile, 2.03% of the memory accuracy of graphics increased. Furthermore, the personal characteristics of the participants also affected visual cognitive work. Therefore, it is expected to improve the visual cognitive work performance of employees for room acoustic design.
Irrelevant background speech causes dissatisfaction and impairs cognitive performance in open‐plan offices. The model of Hongisto (2005, Indoor Air, 15, 458‐468) predicts the relation between cognitive performance and the intelligibility of speech described with an objectively‐measured quantity, the Speech Transmission Index (STI). The model has impacted research in psychology and room acoustics as well as the acoustic design guidelines of offices. However, the model was based on scarce empirical data. The aim of this study was to revise the model based on a systematic literature review, focusing on laboratory experiments manipulating the STI of speech by wide‐band steady‐state noise. Fourteen studies reporting altogether 34 tests of the STI−performance relation were included. According to Model 1 that includes all tests, performance begins to decrease approximately above STI = 0.21 while the maximum decrease is reached at STI = 0.44. Verbal short‐term memory tasks were most strongly and very consistently affected by the STI of speech. The model for these tasks showed a deterioration in performance between STI 0.12 and 0.51. Some evidence of an STI–performance relation were found in verbal working memory tasks and limited evidence in complex verbal tasks. Further research is warranted, particularly concerning task‐specific effects.
Room acoustic parameters of open-plan offices, e.g. ceiling, wall, screen, and furniture absorption, and screen height between workstations, affect strongly sound pressure level (SPL) of speech. The effect depends on the distance from the speaker. The aim of this experimental study was to examine the effect of ceiling, wall, and screen absorption, and screen height on the spatial decay of speech both at short and long distances from the speaker. Twenty-two experimental conditions were built in an open-plan office including 12 workstations. The conditions were combinations of ceiling absorption (2 levels), wall absorption (2 levels), screen absorption (2 levels), and screen height (4 levels). The spatial decay of A-weighted SPL of speech was measured according to ISO 3382-3 in workstations at distances from 2 to 9 m from the speaker. The A-weighted SPL of speech in the nearest workstation, at the distance of 2 m, varied between 53 and 61 dB, and at the distance of 4 m, between 46 and 60 dB. The spatial decay rate of A-weighted SPL of speech, D2,S, varied between 1.3 and 8.5 dB. The results confirmed that ceiling absorption is the most efficient way to increase spatial attenuation, but the attenuation effect also depends on the absorption of vertical surfaces like screens and walls, and the height of the screens. Our study is unique because it is the first experimental study conducted in a full-scale open-plan office, which investigates the impact of several sound absorbing surfaces and screen height simultaneously.
Noise in open-plan offices, and more specifically conversational noise, is a major source of annoyance for employees. The principle of sound masking consists in artificially increasing the background noise in the office, which leads to a decrease in speech intelligibility and therefore a reduction in acoustic annoyance. Nevertheless, the arguments in favour of this technology are based on short-term laboratory studies, whose lack of representativeness limits the application of their conclusions in real open-plan offices. This justifies the present study, which aims to evaluate, in situ and over the long term, the effectiveness of a sound masking system that meets the main scientific and normative recommendations (for example, a masking level below 45 dB(A) and a spectrum with a slope of approximately − 5 dB per octave). Such a sound masking system was installed for several months in an office of a major French banking company. The experiment spanned 26 weeks, 14 of which corresponded to nominal operation of the masking system. The protocol was based on subjective measurements using questionnaires on perceived fatigue, mental workload and perception of the soundscape. The study did not reveal any significant improvement in the assessed psychological factors nor in annoyance caused by office noise. On the contrary, it showed an increase in annoyance caused by noise from office equipment. This highlights the fact that a masking level of 45 dB(A) might already be too high. The results therefore suggest that, in real conditions, a masking system, even if it is used according to specifications that seem to be agreed upon, is not a turnkey solution to the problem of noise in open-plan offices. It is recommended that the installation of these systems be preceded by a holistic analysis of the office: acoustic quality of the room, layout of the workstations and the activities that take place there.
Acoustical privacy is one of the most crucial, yet least satisfying aspects in open-plan offices. Irrelevant background speech impairs acoustic satisfaction and cognitive performance. Assessing acoustical conditions in occupied offices is challenging, and thus room acoustic parameters are commonly determined in unoccupied offices. In German speaking countries the rating level of noise is an important parameter occupational safety and health practitioners in the field often use to assess the acoustical conditions in occupied offices. The rating level denotes the energy-equivalent sound pressure level during a measurement period in an occupied office with speech sounds and takes penalties for tonal, informational and impulsive constituents into account. There is little evidence that the rating level correlates with the well-being, performance or health of office workers. As part of this study 89 different sound conditions under which subjects have to complete a number recall task and a questionnaire in laboratory conditions are evaluated with respect to their relationships with the rating level. In addition, these results are compared to percentile level statistics suggested as an alternative approach to assess the acoustical quality of office workplaces. Higher differences between the 10th and 90th percentile levels measured with fast time weighting lead to lower number recall performances and higher annoyance ratings whilst the rating level does not show any clear relationships.
One of the principal aspects of environmental ergonomics in open-plan offices is the acoustic comfort. Human factors/ergonomics experts should be able to evaluate these spaces in terms of their acoustic condition and propose optimal interventions. We examined the acoustic conditions of a typical open-plan bank office. The acoustic condition of the bank was not desirable, and the inappropriate design of the workstation partitions was one of the major acoustic problems in the bank. We proposed a practical approach for designing an optimal acoustic plan for the workstations and prioritized functional schemes to improve the acoustic conditions of the bank.
We have recently cast doubt (Craik, Govoni, Naveh-Benjamin, & Anderson, 1996; Naveh-Benjamin, Craik, Guez, & Dori, 1998) on the view that encoding and retrieval processes in human memory are similar. Divided attention at encoding was shown to reduce memory performance significantly, whereas divided attention at retrieval affected memory performance only minimally. In this article we examined this asymmetry further by using more difficult retrieval tasks, which require substantial effort. In one experiment, subjects had to encode and retrieve lists of unfamiliar name-nouns combinations attached to people's photographs, and in the other, subjects had to encode words that were either strong or weak associates of the cues presented with them and then to retrieve those words with either intra- or extra-list cues. The results of both experiments showed that unlike division of attention at encoding, which reduces memory performance markedly division of attention at retrieval has almost no effect on memory performance, but was accompanied by an increase in secondary-task cost. Such findings again illustrated the resiliency of retrieval processes to manipulations involving the withdrawal of attention. We contend that retrieval processes are obligatory or protected, but that they require attentional resources for their execution.
The aim of this study was to show how the basic parameters of an open office affect the speech privacy and speech level between two neighboring workstations. The investigation was carried out in laboratory conditions where two adjacent workstations were located. The parameters studied were screen height, room height, ceiling absorption, floor absorption, screen absorption, and masking sound level. Altogether 50 different combinations were studied at three different masking sound levels and normal voice levels. The horizontal sound field was damped by wall absorbers so that the arrangement resembled a pair of workstations in the middle of a large room. The speech privacy improved with increasing masking sound level, ceiling absorption, screen height, and room height, in the order of partial significance. It was possible to reduce speech levels at most by approximately 15 dBA by using the best combination of ceiling absorber and screen height, compared to the situation without absorbers and screens. However, if the masking sound level was low, below 40 dBA, sufficient speech privacy, i.e. low speech intelligibility, could not be reached. The study emphasizes the importance of masking sound as a basic precondition for good speech privacy if normal voice levels are used in the office. The study also gives preliminary evidence that insufficient attenuation of the horizontal sound field in an open office can seriously undermine the attenuation gained from ceiling absorbers and screens. The acoustical design requires simultaneous solutions for masking sound, and the absorption of horizontal and vertical sound fields.
Addresses the possibility that tones disrupt serial recall of visually presented material in the same way as speech. A stream of changing tones is as disruptive of visual serial recall as 4 syllables (Exps 1 and 2). Similar effects were also shown with a repeated syllable that changed only in pitch (Exp 3). Just as for speech, the effect of tones is not at encoding but during storage of the serial lists (Exp 4 and 5). The results suggest that speech and tones are equipotent in their capacity to disrupt short-term memory. A "blackboard" model of working memory to account for the effects is outlined. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
According to several independent field surveys, noise is the most adverse factor of indoor environment in open offices. Speech has been rated as the most distracting sound source. Laboratory experiments have shown that speech impairs the perform-ance of cognitively demanding tasks, e.g. verbal and memory recall tasks. Speech intelligibility determines the distracting power of speech primarily, not the sound pres-sure level of speech. These results should be translated into common language to promote the importance of noise control in open offices. The aim of this study is to suggest a new model that predicts the decrease in work performance as a function of Speech Transmission Index, STI. Subjective speech intelligibility can be evaluated by measuring the STI between office workstations. Work performance is best when speech is absent (STI=0.00), and worst when speech is perfectly understood (STI=1.00). The shape of the performance loss versus STI between 0.00 and 1.00 was based on previously known relation of subjective speech intelligibility and STI. The performance loss starts to increase strongly when STI exceeds 0.20. The in-crease ceases when STI exceeds 0.60. The model was validated using recent ex-perimental data. Although the model ignores, e.g., task demands, habituation, aural effects and loudness of speech, it seems to work as a link between environmental psychology and acoustic design. It can be used directly to promote noise control since the payback time of investments can be estimated by means of improved work performance.
Five experiments demonstrate auditory-semantic distraction in tests of memory for semantic category-exemplars. The effects of irrelevant sound on category-exemplar recall are shown to be functionally distinct from those found in the context of serial short-term memory by showing sensitivity to: The lexical-semantic, rather than acoustic, properties of sound (Experiment 1) and between-sequence semantic similarity (Experiments 1–5) but only under conditions in which the task is free, not serial, recall (Experiment 3) and when the irrelevant sound items are dominant members of a semantic category (Experiment 4). The experiments also reveal evidence of a breakdown of a source-monitoring process
under conditions of between-sequence semantic similarity (Experiments 2–5). Results are discussed in terms of activation and inhibition accounts and support a dynamic, process-oriented, rather than a structurally based, account of forgetting.
We examined the hypothesis that, on verbal fluency, clustering (i.e. generating words within subcategories) is related to temporal-lobe functioning, whereas switching (i.e. shifting between subcategories) is related to frontal-lobe functioning. Tests of phonemic and semantic fluency were administered to 53 patients with focal frontal-lobe lesions (FL), 23 patients with unilateral temporal-lobe lesions (TL) and 55 matched controls. Performance by FL patients was consistent with our hypothesis: in comparison to controls, patients with left-dorsolateral or superior-medial frontal lesions switched less frequently and produced normal cluster sizes on both phonemic and semantic fluency. Performance by TL patients was not consistent across fluency tasks and provided partial support for our hypothesis. On phonemic fluency, TL patients were unimpaired on both switching and clustering. On semantic fluency, TL patients were impaired on switching in comparison to controls and left TL patients produced smaller clusters than right TL patients. The best indices for discriminating the patient groups, therefore, were phonemic-fluency switching (impaired only with frontal lesions) and semantic-fluency clustering (impaired only with temporal-lobe lesions).
Habituation of the orienting response is a pivotal part of selective attention, and previous research has related working memory capacity (WMC) to attention control. Against this background, the purpose of this study was to investigate whether individual differences in WMC contribute to habituation rate. The participants categorized visual targets across six blocks of trials. Each target was preceded either by a standard sound or, on rare trials, by a deviant. The magnitude of the deviation effect (i.e., prolonged response time when the deviant was presented) was relatively large in the beginning but attenuated toward the end. There was no relationship between WMC and the deviation effect at the beginning, but there was at the end, and greater WMC was associated with greater habituation. These results indicate that high memory ability increases habituation rate, and they support theories proposing a role for cognitive control in habituation and in some forms of auditory distraction.
Noise abatement in office environments often focuses on the reduction of background speech intelligibility and noise level, as attainable with frequency-specific insulation. However, only limited empirical evidence exists regarding the effects of reducing speech intelligibility on cognitive performance and subjectively perceived disturbance. Three experiments tested the impact of low background speech (35 dB(A)) of both good and poor intelligibility, in comparison to silence and highly intelligible speech not lowered in level (55 dB(A)). The disturbance impact of the latter speech condition on verbal short-term memory (n=20) and mental arithmetic (n=24) was significantly reduced during soft and poorly intelligible speech, but not during soft and highly intelligible speech. No effect of background speech on verbal-logical reasoning performance (n=28) was found. Subjective disturbance ratings, however, were consistent over all three experiments with, for example, soft and poorly intelligible speech rated as the least disturbing speech condition but still disturbing in comparison to silence. It is concluded, therefore, that a combination of objective performance tests and subjective ratings is desirable for the comprehensive evaluation of acoustic office environments and their alterations.
The aim of this study was to show how absorption and furniture affects speech level and speech transmission index STI at different distances from the speaker. The investigation was carried out in an open-plan office laboratory with 12 workstations (84 m 2). The room acoustics was adjusted by room parameters like ceiling absorption, wall absorption, screen absorption, screen height and masking sound level. Altogether, 18 different combinations were studied using three different masking sound levels and normal voice level. The measurements followed ISO/DIS 3382-3. The study confirmed earlier findings that speech privacy improves with increasing masking sound level, room absorption, and screen height. The spatial decay rate of speech, DL 2,S, ranged between 1.2 and 8.4 dB. The distraction distance, r D, ranged between 2.7 and 37.9 m. The results emphasized the effect of the distance. The effect of each room parameter was small at the nearest workstation and increased significantly with distance. The effect of vertical absorbers was strong which has not been studied before in real setups. Good speech privacy requires simultaneous consideration of masking sound, furniture and screen height, and absorption on both horizontal and vertical room surfaces.
The aim of the study was to determine how the holistic improvement of the indoor environment, especially acoustic environment, affected acoustic satisfaction and the wellbeing of workers in an open-plan office. The study was carried out in an open-plan office of 45 workers which was completely renovated. Special efforts were made to reduce noise and to improve speech privacy. The acoustic improvement included the isolation of noisy activities from the open-plan office area, significant addition of absorption materials and the installation of speech masking system. Room acoustic measurements (ISO 3382-3) and a questionnaire study were carried out both before (N=19) and after (N=20) the renovation. Distraction distance reduced from 5 to 3 metres showing significant improvement of objective speech privacy. Most important was that several positive and statistically significant outcomes could be reported on the basis of the occupant survey. The study provides evidence that the improvement of acoustic satisfaction is possible in open-plan offices provided that all possible architectural and room acoustic means to reduce unnecessary speech in the workstation area are simultaneously taken into account.
For decades, the fundamental processes underlying memory and attention have been understood within an "information processing" framework in which information passes from one processing stage to another, leading eventually to a response. More recently, however, the attempt to build a general theoretical framework for information processing has been largely supplanted in favor of two more recent approaches: mathematical models of processing and direct investigations of brain function. This book reconciles theoretical conflicts in the literature to present an important, analytical update of the traditional information-processing approach by modifying it to incorporate the last few decades of research on memory, attention, and brain functioning. Throughout, the book cogently considers and ultimately refutes recent challenges to the fundamental assumption of the existence of special short-term memory and selective attention faculties. It also draws a key distinction between memory processes operating inside and outside of the focus of attention. The book hopes to foster an understanding of how memory and attention operate together, and how both functions are produced by brain processes.
A series of studies addresses the possibility that tones disrupt serial recall of visually presented material in the same way as speech. A stream of changing tones is as disruptive of visual serial recall as 4 syllables (Experiments 1 and 2). Similar effects were also shown with a repeated syllable that changed only in pitch (Experiment 3). Just as for speech, the effect of tones is not at encoding but during storage of the serial lists (Experiments 4 and 5). The results suggest that speech and tones are equipotent in their capacity to disrupt short-term memory. A "blackboard" model of working memory to account for the effect is outlined.
The Battig and Montague (1969) category norms have been an invaluable tool for researchers in many fields, with a recent literature search revealing their use in over 1600 projects published in more than 200 different journals. Since 1969, numerous changes have occurred culturally that warrant the collection of new normative data. For instance, in the mid-1960s, the waltz was a popular dance, and undergraduates wore rubbers on their feet. To meet the need for updated norms, we report an expanded version of the Battig and Montague (1969) norms, based on responses from three different sites varying in geographical locations within the United States. The norms were expanded to include new categories (e.g., ad hoc categories) and new measures, most notably latencies for the generated responses. Analyses demonstrated high levels of geographical stability across the new sites, with lower and more variable levels of generational stability between the Battig and Montague norms and the current norms.
Noise is the most detrimental factor of the indoor environment in open-plan offices. Speech is the most distracting source of noise. Distraction and speech privacy can be estimated objectively by determining speech intelligibility between workstations. Previously used measurement methods have focused on two neighbouring workstations. However, noise complaints are not restricted to the nearest workstation. The aim of this paper is to suggest a new method to measure and characterize the acoustical conditions of the whole office space, including both short and long distances from the speaker. The method should result in compact and expedient single-number quantities to improve the utilization of the method in building design. The measurement is carried out between workstations along a line consisting of at least 4 workstations. Measurements are made for background noise level, spatial reduction of Speech Transmission Index, STI, and spatial reduction of the SPL of normal effort speech. An omni-directional loudspeaker is used. The acoustic performance of offices could be logically described by three single number quantities: distraction distance, rD, spatial attenuation rate of A-weighted SPL of speech, DL2, and SPL of speech at a distance of 4 metres, Lp,S,4m. The method has been validated in 16 offices which varied significantly in room geometry, furniture and absorption. The differences between offices were unexpectedly large. Recommendations are presented for new target values which are already adopted in two Finnish guidelines.
The aim of this study was to compare different sounds which can be used in open-plan offices to mask distracting speech. Fifty-four subjects were tested in seven sound conditions: speech, silence and five masked speech conditions. The five masking sounds were filtered pink noise, ventilation noise, instrumental music, vocal music and the sound of spring water. They were superimposed on speech. The masked speech conditions corresponded to an acoustically excellent open-plan office in respect to the Speech Transmission Index (STI 0.38). The speech condition (STI 0.62) corresponded to the STI obtained between nearby workstations in an acoustically poor open-plan office. Silent condition (STI 0.00) corresponded to the STI measured between two nearby private office rooms. In each of the seven sound conditions, the subjects performed a short-term memory task, a proofreading task and a creative thinking task and completed a questionnaire on acoustic comfort. Compared to silence condition, short-term memory performance deteriorated in speech condition and in most masked speech conditions. Compared to speech condition, performance improved when speech was masked with spring water sound. Ratings of acoustic satisfaction and subjective workload showed that masked speech conditions subjectively improved the working conditions compared to speech condition. Overall, the performance results and subjective perceptions showed that the spring water sound was the most optimal speech masker whereas vocal music produced negative effects similar to those of speech. The use of constant masking sounds should be preferred in open-plan offices instead of instrumental or vocal music.
Hearing impaired and normal hearing individuals were compared in two within-participant office noise conditions (high noise: 60 L Aeq and low noise: 30 L Aeq ). Performance, subjective fatigue, and physiological stress were tested during working on a simulated open-plan office. We also tested two between-participants restoration conditions following the work period with high noise (nature movie or continued office noise). Participants with a hearing impairment (N = 20) were matched with normal hearing participants (N = 18) and undertook one practice session and two counterbalanced experimental sessions. In each experimental session they worked for two hours with basic memory and attention tasks. We also measured physiological stress indicators (cortisol and catecholamines) and self-reports of mood and fatigue. The hearing impaired participants were more affected by high noise than the normal hearing participants, as shown by impaired performance for tasks that involve recall of semantic information. The hearing impaired participants were also more fatigued by high noise exposure than participants with normal hearing, and they tended to have higher stress hormone levels during the high noise compared to the low noise condition. Restoration with a movie increased performance and motivation for the normal hearing participants, while rest with continued noise did not. For the hearing impaired participants, continued noise during rest increased motivation and performance, while the movie did not. In summary, the impact of noise and restorative conditions varied with the hearing characteristics of the participants. The small sample size does however encourage caution when interpreting the results.
The aim of the present study was to investigate cognitive, emotional, and physiological effects of two open-plan office noise conditions (high noise: 51 LAeq and low noise: 39 LAeq) during work in a simulated open-plan office, followed by four restoration conditions (river movie with sound, only river sound, silence, and office noise) after the work period. Students (N = 47) went through one practice session and two experimental sessions, one each with the low and high noise conditions. In each experimental session they worked for 2 h with tasks involving basic working memory processes. We also took physiological measures of stress (cortisol and catecholamines) and self-reports of mood and fatigue. Analyses indicate that the participants remembered fewer words, rated themselves as more tired, and were less motivated with work in noise compared to low noise. In the restoration phase the participants who saw a nature movie (including river sounds) rated themselves as having more energy after the restoration period in comparison with both the participants who listened to noise and river sounds. Remaining in office noise during the restoration phase also affected motivation more negatively than listening to river sounds or watching the nature movie. The findings bear on the appropriateness of open-plan office designs and the possibilities for restoration available in office settings.
A group of sixty-six adult subjects was given the task of producing as many words as possible beginning with specified letters of the alphabet. The number of words produced during a period of 60 sec correlated highly both with a frequency count derived from the Thorndike-Lorge norms and with estimates derived from the dictionary of the number of words in the English language beginning with each letter. In a second experiment, eight letters representing three levels of difficulty as found in normal subjects were given to thirty brain-damaged and thirty hospitalized control patients. Results in terms of verbal productivity indicated that, for patients of high intelligence, difficult letters (i.e. J and U) showed the greatest discrimination. On the other hand, for patients of low intelligence, easy letters (i.e. F, S, P and T) were more effective in differentiating the brain-damage and control groups. The findings also indicated that difficult letters may be particularly effective in distinguishing between patients with right and left hemisphere damage. An analysis of order of presentation indicated that practice and fatigue effects were not related to verbal fluency when as many as eight letters were administered. It is suggested that the addition of difficult letters to standard word fluency tests may yield more precise discriminations between brain-damaged and control patients when overall level of intellectual functioning is taken into account.
The concept of the Modulation Transfer Function (MTF) can successfully
be applied to evaluate the quality of speech transmission from a
talker to a listener in an auditorium. Typically, depending on the
auditorium acoustics, the intensity modulations contained in the
original sound are to some extent reduced when measured at a listener's
location, especially for higher modulation frequencies. The implementation
of such an acoustical MTF analysis with a sinusoidally modulated
test signal is described in detail. The performance of a sound transmission
system as revealed by the MTF can be expressed in one single index
(the Speech Transmission Index, STI), which relates well to the performance
as determined by intelligibility tests with talkers and listeners.
A review is given of a series of studies on various aspects of the
chain of relations between auditorium acoustics, MTF, STI, and speech
intelligibility, illustrating the use of this approach for estimating
speech intelligibility, either from MTF calculations at the design
stage of an auditorium or from MTF measurements in actual situations.
Mental tasks are susceptible to disruption by concurrent to-be-ignored speech. The goal of the present paper is to examine whether a theoretical framework successfully applied to irrelevant speech effects in serial recall-interference by process-can be extended to verbal tasks in which meaning is the basis of retrieval and to which the irrelevant sound is related to different degrees by meaning. That the semantic characteristics of the to-be-ignored sound interact with the predominance of semantic retrieval in the focal task to determine the degree of disruption is demonstrated in three settings: free recall, category-clustering and fluency. Source monitoring-the difficulty in discriminating episodic information on the basis of the sense modality (visual or auditory) in which it was presented-contributes in part to the disruption by speech. The power of alternative accounts-interference-by-content and attentional capture-to predict these outcomes is also discussed.
The aim was to determine how the perceived work environment, especially acoustic environment, and its effects differed in private office rooms and in open-plan offices. The subjects consisted of 31 workers who moved from private office rooms to open-plan offices and who answered the questionnaire before and after the relocation. Private office rooms were occupied only by one person while open-plan offices were occupied by more than 20 persons. Room acoustical descriptors showed a significant reduction in speech privacy after relocation. The noise level averaged over the whole work day did not change but the variability of noise level reduced significantly. Negative effects of acoustic environment increased significantly, including increased distraction, reduced privacy, increased concentration difficulties and increased use of coping strategies. Self-rated loss of work performance because of noise doubled. Cognitively demanding work and phone conversations were most distracted by noise. The benefits that are often associated with open-plan offices did not appear: cooperation became less pleasant and direct and information flow did not change. Nowadays, most office workers, independent of job type, are located in open-plan offices without the individual needs of privacy, concentration and interaction being analysed. This intervention study consisted of professional workers. Their work tasks mainly required individual efforts, and interaction between other workers was not of primary concern, although necessary. The results suggest that the open-plan office is not recommended for professional workers. Similar intervention studies should also be made for other job types.
Incluye índice Incluye bibliografía Contenido: Introducción. Modelando la memoria y la atención. I. Fenómenos de memoria temporal. Activación de la memoria y enfoque atencional. Fenómenos de memoria de corto plazo reales versus virtuales. II. Fenómenos de atención selectiva. Orientación y filtrado de la atención. Atención y memoria a largo plazo. Foco de atención y conciencia. Observaciones y conclusiones, con pasos hacia una neurociencia.
Abstract This study examined how the intelligibility of irrelevant speech, determined with the Speech Transmission Index (STI), affects demanding cognitive task performance. Experiment was carried out in a laboratory that resembled an open-plan office. Three speech conditions were tested corresponding to a private office (STI = 0.10), an acoustically excellent open office (STI = 0.35) and an acoustically poor open office (STI = 0.65). All conditions were presented at equal level, 48 dBA. The STI was adjusted by the relative levels of speech and masking sound. Thirty-seven students participated in the experiment that lasted for 4 h. All participants performed five tasks in each of the three speech conditions. Questionnaires were used to assess subjective perceptions of the speech conditions. Performance in the operation span task, the serial recall and the activation of prior knowledge from long-term memory were deteriorated in the speech condition with the highest speech intelligibility (STI = 0.65) in comparison with the other two conditions (STI = 0.10 and STI = 0.35). Unlike performance measures, questionnaire results showed consistent differences among all three speech conditions, i.e. subjective disturbance increased with ascending speech intelligibility. Thus, subjective comfort was disturbed more easily than performance. The results support the use of STI as an essential room acoustic design measure in open-plan offices.
Reduction of speech intelligibility in office environments by proper acoustic design would be beneficial in terms of both work performance and subjective comfort. Proper acoustic design requires both the use of high acoustic absorption and an appropriate masking sound.
The extent to which familiar syntax supports short-term serial recall of visually presented six-item sequences was shown by the superior recall of lists in which item pairs appeared in the order of "adjective-noun" (items 1-2, 3-4, 5-6)--congruent with English syntax--compared to when the order of items within pairs was reversed. The findings complement other evidence suggesting that short-term memory is an assemblage of language processing and production processes more than it is a bespoke short-term memory storage system.
Irrelevant speech markedly impairs serial recall of visually presented lists, even though the person is asked to ignore the speech. In this, the first major review of the phenomenon, we conclude that (i) the effect occurs in memory rather than at encoding; (ii) within memory, the disruption occurs as a result of a confluence of information at the phonological rather than at the articulatory stage of coding; (iii) speech does not have privileged access to memory, since its disruptive effects may be attenuated by habituation; and (iv) disruption occurs as a result of the changing state of the auditory channel, not as had previously been thought the phonological similarity of visual and auditory streams, and is particularly sensitive to pitch changes in both speech and non-speech stimuli. These conclusions are discussed in the light of two complementary theoretical constructs: a cascading filter system responsible for the access of speech to memory and a system of coding within memory sensitive to changing state of the stream responsible for disruption of serial order. Recommendations are made also for empirical work to refine these constructs.
A list of ten spoken Swedish sentences was computer edited to obtain new lists with exactly the same content of sound, but with new sentences. A noise was synthesized from the speech material by the computer to produce exactly the same spectrum of speech and noise. The noise was also amplitude modulated by a low frequency noise to make it sound more natural. This material was tested monaurally on 20 normal-hearing subjects. The equality in intelligibility of some of the lists was investigated. Repeated threshold measurements in noise showed a standard deviation of 0.44 dB when the learning effect was outbalanced. Only a small part of the learning effect was due to learning of the word material. Intelligibility curves fitted to the data points in noise and without noise showed maximum steepnesses of 25 and 10%/dB respectively. At constant signal to noise ratio (S/N) the best performance was achieved at a speech level of 53 dB.
A series of experiments explored the role of level, signal-to-noise ratio, and the masking-level difference in the irrelevant speech effect (ISE). In Experiment 1 the detrimental effects of irrelevant sound on serial recall were found to be the same whether the material (speech or music) was presented at a high (75 dB[A]) or low (60 dB[A]) overall level. In Experiment 2, adding pink noise to the speech signal produced a linear improvement in performance with decreasing speech-to-noise ratios. In Experiment 3 the contribution of binaural unmasking to the ISE was found to be negligible. The results (a) confirm that the segmented, changing nature of the irrelevant sound is crucial in producing the ISE and (b) suggest that the adverse effects of disruptive auditory input may be alleviated by introducing additional uniform masking noise.
A dual-task methodology was used to investigate the roles played by executive and phonological aspects of working memory in mental arithmetic. Experiment 1 showed that suppression of articulation impaired the ability to add a pair of briefly presented three-digit numbers. Suppression had no effect when the need to store temporarily was minimized by making the numbers visible throughout calculation. Experiment 2 showed that disrupting executive processes by requiring concurrent performance of a Trails task impaired the ability to add numbers that remained permanently visible. Performance on the Trails task deteriorated as the number of carry operations in the addition increased. Experiment 3 showed that this decline in Trails performance was not simply due to the extra time taken by carrying. These and other features of the results suggest that the carrying component of mental arithmetic places substantial demands on executive processes, whereas the need to retain problem information is met by the phonological loop. The results are consistent with an interpretation of executive processes according to which there is a limit on the capacity to inhibit strongly primed routine operations.
We have recently cast doubt (Craik, Govoni, Naveh-Benjamin, & Anderson, 1996; Naveh-Benjamin, Craik, Guez, & Dori, 1998) on the view that encoding and retrieval processes in human memory are similar. Divided attention at encoding was shown to reduce memory performance significantly, whereas divided attention at retrieval affected memory performance only minimally. In this article we examined this asymmetry further by using more difficult retrieval tasks, which require substantial effort. In one experiment, subjects had to encode and retrieve lists of unfamiliar name-nouns combinations attached to people's photographs, and in the other, subjects had to encode words that were either strong or weak associates of the cues presented with them and then to retrieve those words with either intra- or extra-list cues. The results of both experiments showed that unlike division of attention at encoding, which reduces memory performance markedly, division of attention at retrieval has almost no effect on memory performance, but was accompanied by an increase in secondary-task cost. Such findings again illustrated the resiliency of retrieval processes to manipulations involving the withdrawal of attention. We contend that retrieval processes are obligatory or protected, but that they require attentional resources for their execution.
Abstract
Abstract Speech is the most distracting sound in (open-plan) offices. Several laboratory studies have shown that speech impairs the performance of, for example, reading and short-term memory. It is not the sound level of speech that determines its distracting power but its intelligibility, which can be physically determined by measuring the Speech Transmission Index (STI). The aim of this study was to develop a mathematical model that predicts how much the performance is reduced due to speech of varying intelligibility. The model was based on the literature according to which performance decrements have been 4–45% depending on the task. The best performance occurs when speech is absent (STI = 0.0), and the strongest performance decrement occurs when speech is perfectly heard (STI = 1.0). The shape of the performance vs. STI between 0.0 and 1.0 was adopted from the general speech intelligibility theory. The performance starts to decrease when STI exceeds 0.2. Highest performance decrease is reached already when STI exceeds 0.60.