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Psychophysiological stress response to traffic speed, road surface, and vegetation in urban environments
Abstract
The acoustic environment in urban spaces is often dominated by human-made noise sources, with road traffic noise as the most pervasive. Meanwhile, urban planning often overlooks how soundscape can impact citizens' well-being. This study combined virtual reality, biometric sensing, and questionnaires to evaluate how urban design measures targeting road traffic noise affect, beyond acoustic characteristics, psychological and physiological stress indicators. Participants (N=37) were immersed in a virtual urban environment with passing vehicles at different speeds (20,30, 50 km/h) over different road surface types and maintenance levels (new vs. deteriorated asphalt concrete and cobblestones) and varying green infrastructure (Green View Index: 0%, 14%, 26%). Noise stimuli were captured through CPX measurements and subsequently auralized, resulting in signals with LAeq spanning a 20 dBA range. Phasic skin conductance (SC), heart rate (HR), and high-frequency heart rate variability (HF-HRV) were recorded, while noise annoyance and cognitive performance were measured through self-report. Noise annoyance consistently increased with poorer pavement conditions and higher speeds. Speed was linked to high phasic SC and HR, while road surface type increased phasic SC and reduced HF-HRV from new to deteriorated asphalt and cobblestones, indexing heightened physiological stress impacting the autonomic nervous system regulation in response to less favourable road/speed conditions. Greenery, at the GVI levels studied, did not impact physiological responses or cognition but minimally reduced noise annoyance. These findings suggest that enforcing lower speed limits and ensuring smoother, well-maintained road surfaces in urban areas can lessen the biological alert state activation while reducing psychological stress.
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This chapter explores the broad impact of noise, highlighting its non-auditory health effects. It is well acknowledged that noise as an environmental stressor disrupts daily life by affecting concentration, communication, rest, and sleep. Beyond these acute effects of noise, the understanding of the health effects of long-term exposure to noise, including the physiological mechanisms behind them, has evolved significantly over the years. Environmental noise is clearly an increasing concern for public health, and current knowledge underscores the urgency of comprehensive approaches to mitigate the health effects of environmental noise.
To date, more and more European cities are systematically working to expand the proportion of their street network with a speed limit of 30 km/h. This paper endeavored to assess the effectiveness of city-wide 30 km/h speed limits in Europe. In an effort to condense research outputs, a quantitative approach along with qualitative assessments were implemented. This study described the changes in safety, environment, energy, traffic, livability, and health before and after the phased implementation of city-wide 30 km/h speed limits. The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Results from 40 different cities across Europe, including Brussels, Paris, and Zurich, indicated that reductions in speed limits improved road safety by decreasing the likelihood of crash risk and the severity of crashes that do occur. On average, the implementation of 30 km/h speed limits in European cities demonstrated a 23%, 37%, and 38% reduction in road crashes, fatalities, and injuries, respectively. Lower speed limits also yielded environmental benefits, with emissions decreasing on average by 18%, noise pollution levels by 2.5 dB, and fuel consumption by 7%, indicating enhanced fuel efficiency and reduced environmental impact. Encouraging citizens to embrace walking, cycling and utilizing public transit services can further contribute to a safer and environmentally sustainable urban environment.
The detection of psychological loads, such as stress reactions, is receiving greater attention and social interest, as stress can have long-term effects on health [1]. Acoustic stimuli, especially noise, are investigated as triggering factors. The application of physiological measurements in the detection of psychological loads enables the recording of a further quantitative dimension that goes beyond purely perceptive questionnaires. Thus, unconscious reactions to acoustic stimuli can also be captured. The numerous physiological signals and possible experimental designs with acoustic stimuli may quickly lead to a challenging implementation of the study and an increased difficulty in reproduction or comparison between studies. An unsuitable experimental design or processing of the physiological data may result in conclusions about psychological loads that are not valid anymore. The systematic review according to the PRISMA standard presented here is therefore intended to provide guidance and a basis for further studies in this field. For this purpose, studies were identified in which the participants’ short-term physiological responses to acoustic stimuli were investigated in the context of a listening test in a laboratory study. A total of 37 studies met these criteria and data items were analysed in terms of the experimental design (studied psychological load, independent variables/acoustic stimuli, participants, playback, scenario/context, duration of test phases, questionnaires for perceptual comparison) and the physiological signals (measures, calculated features, systems, data processing methods, data analysis methods, results). The overviews show that stress is the most studied psychological load in response to acoustic stimuli. An ECG/PPG system and the measurement of skin conductance were most frequently used for the detection of psychological loads. A critical aspect is the numerous different methods of experimental design, which prevent comparability of the results. In the future, more standardized methods are needed to achieve more valid analyses of the effects of acoustic stimuli.
The literature lacks a model of the specific environmental element that induces restoration. Thus, this study contributes to the development of sustainable and healthy environments by examining the effect of the soundscape and landscape experience on psycho-physiological restoration from the audiovisual interaction perspective. It examined various urban and natural environments to propose a restoration model for environmental design application. Sixty participants evaluated three each of urban, waterfront, and green environments using virtual reality technology. The audiovisual characteristics of environments were quantified, and environmental perception was assessed per 14 audiovisual element identifications, six perceived affective qualities, and six overall environmental qualities. The restoration responses were classified as psychological and physiological. Accordingly, 10 restoration models that can interpret design factors of the urban environment with a maximum correlation of 0.80 and an explanatory power of 22% emerged from urban audiovisual design elements and psycho-physiological responses. Consequently, to improve restoration response, visually attractive and spatial-natural landscapes and acoustically supportive and tranquil soundscapes should be created. Moreover, urban designers can use the models to clearly identify physical characteristics that should be prioritized when promoting the health improvement of urbanites. Furthermore, the study findings can serve as basic data for the development of healthy environments.
Stakeholder participation is an important component of modern urban planning processes. It can provide information about potential social conflicts related to specific urban planning scenarios. However, acquiring feedback from stakeholders is usually limited to explicit response types such as interviews or questionnaires. Such explicit response types are not suitable for the assessment of unconscious responses to specific parameters of an urban planning scenario. To address this limitation, we propose an approach for the assessment of affective and stress responses using implicit measures. Using a measure for electrodermal activity (EDA) and a virtual reality (VR)-based 3D urban model, we demonstrate how implicit physiological measurements can be visualized and temporally matched to specific parameters in an immersive representation of an urban planning scenario. Since this approach is supposed to support conventional stakeholder participation processes in urban planning, we designed it to be simple, cost-effective and with as little task interference as possible. Based on the additional insights gained from measuring physiological responses to urban planning scenarios, urban planners can further optimize planning scenarios by adjusting them to the derived implicitly expressed needs of stakeholders. To support simple implementation of the suggested approach, we provide sample scripts for visualization of EDA data. Limitations concerning the evaluation of raw EDA data and potentials for extending the described approach with additional physiological measures and real-time data evaluation are discussed.
Lärm ist heutzutage ein großer Faktor, der die Gesundheit vieler Menschen beeinträchtigt. Dabei entstehen neben den direkten Schäden am Gehör, den auralen Lärmeffekten, auch weitere, nicht direkt gehörbezogene gesundheitliche Schäden z.B. durch psychischen Stress. Diese werden als extra-aurale Lärmeffekte beschrieben, mit denen auch eine mögliche schlechtere kognitive Leistung einhergeht.
In früheren Untersuchungen konnte die Schärfe eines Geräuschs bereits mit einer höheren Lästigkeit des Geräuschs in Zusammenhang gebracht werden. Um extra-aurale Effekte von Geräuschen besser und schneller beurteilen zu können, wurde in dieser Studie der psychoakustische Parameter der Schärfe mit einer physiologischen Stressreaktion und kognitiven Leistungen in Zusammenhang gebracht. Die Stressreaktion wurde durch die Messung der Hautleitfähigkeit als physiologischer Parameter erfasst, die kognitive Leistung mit Hilfe des Konzentrations-Leistungs-Tests (KLT). Da Stressreaktionen auch unbewusst ablaufen können, kann eine physiologische Stressmessung auch solche Reaktionen anzeigen, die mit Hilfe einer rein perzeptiven
Stressbewertung durch die Proband*innen nicht erfasst werden.
Im Rahmen der vorgestellten Studie wurde ein Hörversuch konzipiert, bei dem die Proband*innen den KLT bearbeiteten, welcher aus mathematischen Aufgaben besteht. In den jeweiligen Durchläufen wurden zusätzlich verschiedene Geräusche, die sich in ihrer Schärfe unterschieden, den Proband*innen präsentiert. Die gleichzeitig erfassten physiologischen Daten gaben Aufschluss darüber, unter welchen Testbedingungen eine erhöhte Stressreaktion vorlag.
Urban areas are continuously growing, and densification is a frequent strategy to limit urban expansion. This generally entails a loss of green spaces (GSs) and an increase in noise pollution, which has negative effects on health. Within the research project RESTORE (Restorative potential of green spaces in noise-polluted environments), an extended cross-sectional field study in the city of Zurich, Switzerland, is conducted. The aim is to assess the relationship between noise annoyance and stress (self-perceived and physiological) as well as their association with road traffic noise and GSs. A representative stratified sample of participants from more than 5000 inhabitants will be contacted to complete an online survey. In addition to the self-reported stress identified by the questionnaire, hair cortisol and cortisone probes from a subsample of participants will be obtained to determine physiological stress. Participants are selected according to their dwelling location using a spatial analysis to determine exposure to different road traffic noise levels and access to GSs. Further, characteristics of individuals as well as acoustical and non-acoustical attributes of GSs are accounted for. This paper presents the study protocol and reports the first results of a pilot study to test the feasibility of the protocol.
Urban stress is one of today’s most critical health challenges that urban stakeholders need to urgently address. However, while the positive role of nature for mental health and stress level reduction has been widely reported, the role distinct urban green infrastructure design characteristics play in citizen stress level reduction is yet to be understood. This paper presents a novel methodology where virtual reality, eye-tracking technologies, biometric sensing for heart rate variability, and participant questionnaires have been combined, to evaluate the psychological and physiological stress level reduction capacity of urban green infrastructure. 30 subjects have participated in a virtual reality immersion of 12 urban squares. 360° images were captured for each square, and mapped on a virtual sphere surrounding the participant. For each urban square, the green view index was computed using semantic image classification, and based on the obtained green view index values, the images were organized in two blocks: green >35% and non-green <20%. The eye-tracking data showed significant differences between green and non-green blocks. Fixation counts decreased in the green image block, which is an indicator of stress reduction. The perceived restorativeness scale questionnaire also reported highly significant differences with higher global scores for the green image block.
Background
The city of Zurich progressively pursuits a strategy of reducing road traffic noise by lowering the speed limit to 30 km/h on street sections that exceed the legal noise limits.
Study goal
To evaluate the effects of the reduced speed limit on noise levels (Lday and Lnight), noise annoyance, self-reported sleep disturbance, perceived road safety, and – in particular, to elucidate if the reduced speed limit leads to a shift of exposure-response relationships towards lower effects.
Methods
We surveyed about 1300 randomly sampled inhabitants, in a repeated measures study, before and after the speed rule changeover from 50 km/h to 30 km/h along 15 city street sections, by postal questionnaire. Concurrently, individual noise exposure calculations based on traffic counts and on-site speed measurements were carried out before and after the changeover.
Results
Road traffic noise Leq's at the loudest façade point dropped by an average of 1.6 dB during day and 1.7 dB at night. A statistically significant decrease of noise annoyance and of self-reported sleep disturbances was observed, as well as a moderate but significant increase of perceived road safety. Most importantly, the exposure-response relationships for annoyance and sleep disturbance were shifted towards lower effects in the 30 km/h condition by, depending on receiver point, between about 2 dB and 4 dB during the day and about 4 dB at night, indicating lower effects at the same average level. This is a hint that, in addition to lower average exposure levels alone, other factors related to the lower driving speed additionally reduce noise annoyance and sleep disturbance.
Conclusions
City dwellers probably benefit from traffic speed reductions to a greater degree than would be expected from the reduction in average level attained by the lower driving speed alone.
Noise pollution is one of the most common workplace hazards. Noise exposure may induce auditory and extra-auditory physiological and psychological alterations that affect job performance, safety, comfort, and wellbeing. Recent research showed a connection between frequency components of noise and health outcomes, annoyance, physiological and psychological changes. This study investigated whether and how the activation of different typologies of industrial noises set at three different sound levels induced increases in electrodermal activity (EDA) and the heart rate variations differently. A laboratory listening test was performed for the study, in which 24 subjects were exposed to the activation of different industrial noises: Low Frequency, High Frequency, and Modulated noises at Low, Medium, and High sound levels, while some physiological responses were recorded. The noise stimuli were also evaluated based on a self report questionnaire. Results show that the EDA variation increases as the Sound Level increases and is higher at HF. In contrast, no relevant changes have been found in RR variation. EDA changes are also related to the perception of the Valence dimension of the noise environment, while RR variations not. The findings of this study emphasized that the changes in EDA depend on the sound levels and frequency content of industrial noise typologies, as well as on the perception of their Valence.
Road traffic noise is one of the most prominent sources of urban noise pollution. Recently, as a result of the electrification of vehicles, lower noise levels are expected in urban areas at speeds below 50 km/h. The commonly used physical descriptor, the A-weighted sound pressure level, does not sufficiently characterize the perceived annoyance of either combustion engine or electric passenger car pass-by noises. Psychoacoustical descriptors are advantageous for characterization purposes. The objective of this study was to evaluate the perceived annoyance caused by the noise from internal combustion engine, electric, and hybrid passenger cars using psychoacoustical properties. To achieve this objective, the following steps were conducted. First, the binaurally recorded sounds of 40 cars from different brands with different motorization were presented to the subjects who indicated the intensity of their perceived annoyance on a quasi-continuous scale. Second, the signal and psychoacoustical properties of the recorded sounds were analyzed. Third, a new annoyance index was developed, based on annoyance judgments and signal and psychoacoustical properties, to characterize the annoyance caused by pass-by noises. One of the novel aspects of this study is the consideration of not only the pass-by sounds of the internal combustion engine passenger cars, but also the pass-by sounds of hybrid and electric passenger cars. An acceleration from idle to a target speed of 50 km/h was selected as a traffic pass-by situation, which differs from those considered in previous studies. The results of the study show that psychoacoustical properties, such as loudness, tonality, roughness, and fluctuation strength, are very useful to characterize the annoyance perception, which is caused by single passenger car pass-by sounds in the above mentioned traffic situation. The developed index, which is a weighted combination of chosen psychoacoustical properties, can be very useful for traffic planning and traffic noise prevention measures.
This article analyses the most recent studies on urban traffic noise. About 67 relevant articles on urban road traffic noise and its mitigation strategies were preferred for a critical review. Only 5.97% of items describe how to monitor and record the noise measurement for urban roads, while 7.46% of articles enumerated urban traffic noise pollution exposure. 29.85% of articles proposed a model to evaluate noise reduction effects and predict the noise level. Also, many articles reported noise map generation and its analysis. 56.71% of articles described the noise mitigation strategies in detail, concerning noise control by green vegetation, land use planning, low noise tire and pavement material, noise reduction through façade shielding. Noise pollution standards are being breached in all areas. There is a need for the proper implementation of rules and regulations. Therefore, noise mitigation strategies such as designing noise barriers and other noise control materials are needed. Finally, it is summarized that economic and low-cost optimized noise pollution mitigation strategies like ingeniously made noise barriers, vegetation and landscaping are need of the hour for urban areas of developing countries.
We used VR to examine the buffering effects of vertical greenery against stressors. • Self-report measures show vertical greenery prevented reduction in positive affect. • Heart rate variability suggests vertical greenery prevented increase in stress. • Our results indicate that vertical greenery can be used to buffer stress.
Cognitive load plays an important role during learning and working, as it has been linked to well-functioning cognitive processes, performance, burnout and depression. Nonetheless, attempts to assess cognitive load in real-time by means of physiological data have been proven difficult, and interpreting these data remains challenging. The aim of this study is to examine whether and how well experienced cognitive load can be measured through psycho-physiological data. The approach of this study is rather unique, for a combination of reasons. First, this study takes a multimodal approach, monitoring EDA (electrodermal activity), EEG (electroencephalography) and EOG (electrooculography). Second, this study is based on a relatively intensive data collection (N = 46) in a controlled lab setting in which varying cognitive load levels are deliberately induced. Finally, not only focussing on statistical significance but also on the size of the association gives insights into how suitable physiological markers are to measure cognitive load. Results from a multilevel analysis suggest that the following physiological markers might be related to cognitive load, for example, in an industrial context: the rate and the duration of skin conductance responses, the alpha power, the alpha peak frequency and the eye blink rate. About 22.8% of the variance in self-reported cognitive load can be explained using these five measures.
Road pavement develops distresses over time, which increase tyre/road noise. This work focuses on the impact of these distresses on environmental noise. To calculate the environmental noise, a method to transform Close ProXimity (CPX) measurement results into the required input for traffic noise models was defined and used. The tyre/road noise levels were determined by the CPX method for three types of pavement, with three types of distress, at three different speed levels. The study was carried out in the city center of Guimarães, a medium-sized Portuguese city. Using the NMPB model, 18 noise maps were produced for the passing of one single vehicle, taking into account two levels of distress (50% and 100%) for the pavement. The presence of distresses increased the noise, calculated at control points, by up to 7.1 dBA, and the percentage of the population exposed to levels over 45 dB was more than 11%. It was shown that pavement maintenance at early stages of distress development is, particularly for low-speed roads, very important to reduce environmental noise and population exposure. A comprehensive selection of the type of surface and speed control policies can mitigate the impact of a lack of maintenance.
The repeated-measures factorial design is a quantitative method for exploring the way multiple variables interact on a single variable for the same person (Field, 2009). This chapter first outlines the design, considering its significance and utility in relation to South African research. Next, a theoretical framework is applied to show how earworms may be sustained in working memory. Then, a segment of research is presented to provide an example of this design. Within this example, the ethics of using such a methodology are explored, as exemplified by the application to earworms. This discussion highlights the methodological value, particularly in relation to the South African context in which the research is located.
Objective:
Physical or mental imbalance caused by harmful stimuli can induce stress to maintain homeostasis. During chronic stress, the sympathetic nervous system is hyperactivated, causing physical, psychological, and behavioral abnormalities. At present, there is no accepted standard for stress evaluation. This review aimed to survey studies providing a rationale for selecting heart rate variability (HRV) as a psychological stress indicator.
Methods:
Term searches in the Web of Science®, National Library of Medicine (PubMed), and Google Scholar databases yielded 37 publications meeting our criteria. The inclusion criteria were involvement of human participants, HRV as an objective psychological stress measure, and measured HRV reactivity.
Results:
In most studies, HRV variables changed in response to stress induced by various methods. The most frequently reported factor associated with variation in HRV variables was low parasympathetic activity, which is characterized by a decrease in the high-frequency band and an increase in the low-frequency band. Neuroimaging studies suggested that HRV may be linked to cortical regions (e.g., the ventromedial prefrontal cortex) that are involved in stressful situation appraisal.
Conclusion:
In conclusion, the current neurobiological evidence suggests that HRV is impacted by stress and supports its use for the objective assessment of psychological health and stress.
This paper describes a systematic review (1980–2014) of evidence on effects of transport noise interventions on human health. The sources are road traffic, railways, and air traffic. Health outcomes include sleep disturbance, annoyance, cognitive impairment of children and cardiovascular diseases. A conceptual framework to classify noise interventions and health effects was developed. Evidence was thinly spread across source types, outcomes, and intervention types. Further, diverse intervention study designs, methods of analyses, exposure levels, and changes in exposure do not allow a meta-analysis of the association between changes in noise level and health outcomes, and risk of bias in most studies was high. However, 43 individual transport noise intervention studies were examined (33 road traffic; 7 air traffic; 3 rail) as to whether the intervention was associated with a change in health outcome. Results showed that many of the interventions were associated with changes in health outcomes irrespective of the source type, the outcome or intervention type (source, path or infrastructure). For road traffic sources and the annoyance outcome, the expected effect-size can be estimated from an appropriate exposure–response function, though the change in annoyance in most studies was larger than could be expected based on noise level change.
The present study analysed the effects of floor impact noise on humans using both psychological and physiological methods. Floor impact noises caused by a standard impact source (i.e. impact ball) and five real impact sources (e.g., human footsteps and dropped objects) were recorded as sound stimuli. During the laboratory experiments, two factors that impact psychophysiological responses were considered: (1) types of impact sources (standard or real sources) and (2) the levels of floor impact noise ranging from 31.5 to 63 dBA in terms of A-weighted maximum sound pressure level (LAFmax). Twenty-one normal-hearing subjects were then asked to judge the noticeability and annoyance caused by the floor impact noises. Meanwhile, the subjects' physiological responses (heart rate: HR, electrodermal activity: EDA, and respiration rate: RR) were monitored throughout the experiments. Noise annoyance and noticeability increased with increases in noise levels, the impact ball resulted in higher noticeability and annoyance ratings than real sources. All physiological measures varied significantly with noise exposure; HR decreased, whereas EDA and RR increased. The results show that the physiological responses were not affected by the type of noise source. In addition, the noise level was found to be significantly related to EDA and RR changes, whereas the relationship between the noise level and HR was not found to be significant.
AKtools is available from: http://ak.tu-berlin.de/aktools
The acquisition, processing, and inspection of audio data plays a central role in the everyday practice of acousticians. However, these steps are commonly distributed among different and often closed software packages making it difficult to document this work. AKtools includes Matlab methods for audio playback and recording, as well as a versatile plotting tool for inspection of single/multi channel data acquired on spherical, and arbitrary spatial sampling grids. Functional blocks cover test signal generation (e.g. noise, sweeps), spectral deconvolution, transfer function inversion using frequency dependent regularization, spherical harmonics transform and interpolation among others. To foster reproducible research, AKtools is available under the open software European Union Public Licence (EUPL) allowing everyone to use, change, and redistribute it for any purpose.
Computerized room acoustics
modeling has been practiced for almost 50 years up to date. These modeling techniques play an important role in room acoustic design nowadays, often including auralization, but can also help in the construction of virtual environments for such applications as computer games, cognitive research, and training. This overview describes the main principles, landmarks in the development, and state-of-the-art for techniques that are based on geometrical acoustics principles. A focus is given to their capabilities to model the different aspects of sound propagation: specular vs diffuse reflections, and diffraction.
Studies have shown that natural environments can enhance health and here we build upon that work by examining the associations between comprehensive greenspace metrics and health. We focused on a large urban population center (Toronto, Canada) and related the two domains by combining high-resolution satellite imagery and individual tree data from Toronto with questionnaire-based self-reports of general health perception, cardio-metabolic conditions and mental illnesses from the Ontario Health Study. Results from multiple regressions and multivariate canonical correlation analyses suggest that people who live in neighborhoods with a higher density of trees on their streets report significantly higher health perception and significantly less cardio-metabolic conditions (controlling for socio-economic and demographic factors). We find that having 10 more trees in a city block, on average, improves health perception in ways comparable to an increase in annual personal income of 10,000 higher median income or being 7 years younger. We also find that having 11 more trees in a city block, on average, decreases cardio-metabolic conditions in ways comparable to an increase in annual personal income of 20,000 higher median income or being 1.4 years younger.
We explored Google Street View (GSV) as a street-level, urban greenery assessment tool. Street-level greenery has long played a critical role in the visual quality of urban landscapes. This living landscape element can and should be assessed for the quality of visual impact with the GSV information, and the assessed street-level greenery information could be incorporated into urban landscape planning and management. Information on street-level views of urban greenery assessment, however, is rare or nonexistent. Planners and managers’ ability to plan and manage urban landscapes effectively and efficiently is, therefore, limited. GSV is one tool that might provide street-level, profile views of urban landscape and greenery, yet no research on GSV for urban planning seems available in literature. We modified an existing Green View Index (GVI) formula and conducted a case study assessment of street greenery using GSV images in the area of East Village, Manhattan District, New York City. We found that GSV to be well suited for assessing street-level greenery. We suggest further that the modified GVI may be a relatively objective measurement of street-level greenery, and that GSV in combination with GVI may be well suited in guiding urban landscape planning and management.
The Bayesian Information Criterion (BIC) is widely used for variable selection in mixed effects models. However, its expression is unclear in typical situations of mixed effects models, where simple definition of the sample size is not meaningful. We derive an appropriate BIC expression that is consistent with the random effect structure of the mixed effects model. We illustrate the behavior of the proposed criterion through a simulation experiment and a case study and we recommend its use as an alternative to various existing BIC versions that are implemented in available software.
This paper aims to clearly establish the origin and evolution of the shared space concept from a New Zealand perspective by reviewing the literature in the disciplines of both urban design and transportation engineering. The review process involves investigating the use and function of a public road space in the context of the changing of public expectations and how this can relate to a number of interconnected street design approaches (e.g. traffic calming and self-explaining roads (SERs)). These approaches have been used to minimise the influence of motor vehicles since the beginning of the automobile era. The shared space concept, when applied in public road environments in activity centres, has increasingly been embraced by urban planners, transportation engineers and regulatory agencies. A shared space diverges from a conventional road where all road users are encouraged to legitimately occupy the same road space with little physical separation. To achieve this in a safe and efficient manner, the design aims to reduce the dominance of the motor vehicle by promoting pedestrian and cycling activity and utilising the road space as a ‘place’ in addition to its ‘transport’ mobility and access purposes. Given the fundamental conceptual differentiation between a traffic-calmed street and a shared space, the paper argues that there are certain design elements, constituting a shared space, and without them, it would be difficult for a public street to function as a genuine shared space for all road users.
In this paper, annoyance ratings from traffic noise recorded on cobblestones, dense asphalt, and open asphalt rubber pavements are assessed with regard to car speeds and traffic densities. It was found that cobblestones pavements are the most annoying; also while open asphalt rubber pavement imposes less annoyance than dense asphalt it is not significantly different. Higher car speeds always lead to greater annoyance, as does higher traffic densities. LAeq and LAmax correlate well with annoyance, but loudness is the best predictor. Roughness and sharpness exhibit inconsistent interactions.
Traffic noise exposure has detrimental effects on human health, including both auditory and nonauditory impacts. As one such nonauditory factor, individuals and communities in different countries may exhibit different patterns of noise sensitivity and corresponding tolerance levels, leading to a change in overall noise perception. This paper investigated the cross-country differences in psychophysiological responses to traffic noise exposure between Indian and British individuals. A psychophysiological signal-based [heart rate variability (HRV) and skin conductance response (SCR)] listening experiment was conducted in India and the United Kingdom to analyze changes in noise perception and psychophysiological responses resulting from exposure to the same noise stimuli. HRV analysis indicated greater cardiovascular impact in the British group due to a significant increase in heart rate (W = 653, p < 0.01). Also, a significant increase in the SCR (W = 535, p < 0.001) was noted, indicating a greater level of physiological stress among British participants due to traffic noise stimuli. These findings highlight the difference in noise perception due to cross-country variation using psychophysiological responses. Understanding these cross-country differences can inform targeted interventions and policies to mitigate the adverse effects of traffic noise on human well-being.
The evaluation of acoustic environments using the soundscape approach offers the possibility of a holistic analysis. Physiological measurements can complement this approach in order to provide continuous information on the listener's physiological response to the acoustic environment and also record unconscious responses. However, it is essential to clarify which differences in the soundscape characteristics can induce significant changes in the physiological response of the listener. In addition to physiological measurements, listening tests in virtual reality can complement the approach to include soundscape context in laboratory studies to a greater extent. The study conducted in this paper therefore represents a preliminary study for experiments in virtual reality and investigates the reaction of the participants' skin conductance to various soundscape recordings in a laboratory setting. The analysis of the physiological data reveals aspects of soundscapes that are more likely to elicit a stress response or relaxation and shows how much soundscape recordings need to differentiate from each other such that physiological measurements can add value to the holistic soundscape approach.
Emerging technologies of virtual reality (VR) and augmented reality (AR) are enhancing soundscape research, potentially producing new insights by enabling controlled conditions while preserving the context of a virtual gestalt within the soundscape concept. This study explored the ecological validity of virtual environments for subjective evaluations in soundscape research, focusing on the authenticity of virtual audio-visual environments for reproducibility. Different technologies for creating and reproducing virtual environments were compared, including field recording, simulated VR, AR, and audio-only presentation, in two audio-visual reproduction settings, a head-mounted display with head-tracked headphones and a VR lab with head-locked headphones. Via a series of soundwalk- and lab-based experiments, the results indicate that field recording technologies provided the most authentic audio-visual environments, followed by AR, simulated VR, and audio-only approaches. The authenticity level influenced subjective evaluations of virtual environments, e.g., arousal/eventfulness and pleasantness. The field recording and AR-based technologies closely matched the on-site soundwalk ratings in arousal, while the other approaches scored lower. All the approaches had significantly lower pleasantness ratings compared to on-site evaluations. The choice of audio-visual reproduction technology did not significantly impact the evaluations. Overall, the results suggest virtual environments with high authenticity can be useful for future soundscape research and design.
Environmental noise control regulations typically employ noise level descriptors to set limits for noise exposure. However, other characteristics of noise, such as frequency content, temporal patterns and masking, have been proven to influence the perception of acoustic environments. In this sense, psychoacoustic indicators offer an objective means of establishing relationships between physical characteristics of noise and the human auditory sensation phenomena. This study explored psychoacoustic indicators of pass-by vehicle noise across different vehicle categories, driving speeds, and temperatures. Moreover, the indicators were exploited as features to train a classification algorithm to predict vehicle category. Over 2000 vehicle noise samples were collected using the Statistical Pass-By (SPB) method, categorized into three classes according to ISO 11819-1, besides an additional class for delivery vans. Correction coefficients were obtained for temperature and speed to noise levels, loudness, roughness, sharpness and fluctuation strength. The differences in these indicators based on vehicle category were then discussed. A vehicle-category predictive model using the three vehicle categories defined in ISO 11819-1 yielded 84% accuracy. Including vans as an extra vehicle category dropped accuracy to 72% due to their misclassification with passenger cars. Combining these two categories increased overall accuracy to 86%. These findings could enable a less visual-dependent vehicle categorization so that vehicle fleets worldwide are more consistently classified in terms of noise. Additionally, psychoacoustic indicators appear to be valuable features for vehicle classification systems aimed to resemble the human auditory experience.
The relationship between transport noise and health outcomes is complex, in part because of the large number of factors involved as well as the range of health impacts, both direct and indirect. To enable the reader to come to grips with the complexity, we have divided the health outcomes into groups: those that are more directly linked to transport noise exposure and those that are more indirectly linked. Four health outcomes, namely annoyance, cognitive disruption, sleep problems, and noise-induced hearing loss, can be directly attributable to transport noise exposure. Less direct outcomes are stress, mental health, metabolic health, cardiovascular health, and overall health-related quality of life. Stress may occur as a direct response to noise, or may occur in response to the aforementioned direct effects. The stress response is a survival mechanism in the short term, but in the long term, stress may lead to systemic health conditions, namely metabolic and cardiovascular outcomes, and to mental health conditions. Finally, a global health outcome that incorporates all of the more direct outcomes is health-related quality of life. Other exposures associated with transport noise that may explain parts of the health outcomes need to be acknowledged, including exposure to social inequities, air pollution, and vibration. These may all be more likely to be experienced by people who are exposed to transport noise in the community and may thus influence the outcomes. Finally, transport noise appears to have more impact on health in those who are noise sensitive, thus noise sensitivity is a key moderator of all the effects observed.
This research aims to study the independent and interaction effects of aural and visual indicators on soundscape descriptors in the residential area. A virtual reality (VR) experiment was conducted to reproduce audio-visual stimuli and to collect subjective data using the questionnaire. Typical visual elements and aural environment in residential areas were reproduced using Unity software. Ten audio-only stimuli and 42 audio-visual stimuli (combination of 14 visual stimuli and three aural stimuli) were evaluated for various soundscape descriptors by 32 normal-hearing participants. There are four research findings. Firstly, a visual distraction was found on the effect of crowd sound on pleasantness. Secondly, the independent effects of indicators were analyzed. The sound of heavy traffic negatively affects pleasantness, while no significant difference has been found between no traffic and light traffic conditions. The crowd sound and PgVI (Playground View Index) positively affect eventfulness, while roughness and GVI (Green View Index) have a negative effect on eventfulness. Thirdly, traffic sound was found as a moderator of other indicators’ effect on pleasantness and eventfulness. For instance, GVI (Green View Index) can positively affect pleasantness in no traffic and light traffic conditions, while GVI does not affect pleasantness in heavy traffic conditions. Lastly, the present study did not find calmness correlated with eventfulness in residential areas, contrary to the previous studies. A possible explanation for this result might be that the correlation between descriptors is context-dependent.
Virtual reality is becoming an important tool for studying the interaction between pedestrians and road vehicles, by allowing the analysis of potentially hazard situations without placing subjects in real risk. However, most of the current simulators are unable to accurately recreate traffic sounds that are congruent with the visual scene. This has been recognized as a fault in the virtual audio-visual scenarios used in such contexts. This study proposes a method for delivering a binaural auralization of the noise generated by a moving vehicle to an arbitrarily located moving listener (pedestrian). Building on previously developed methods, the proposal presented here integrates in a novel way a dynamic auralization engine, thus enabling real-time update of the acoustic cues in the binaural signal delivered via headphones. Furthermore, the proposed auralization routine uses Close ProXimity (CPX) tyre-road noise signal as sound source input, facilitating the quick interchangeability of source signals, and easing the noise collection procedure. Two validation experiments were carried out, one to quantitatively compare field signals with CPX-derived virtual signal recordings, and another to assess these same signals through psychoacoustic models. The latter aims to assure that the reproduction of the synthesized signal is perceptually similar to one occurring on pedestrian/vehicle interactions during situations of street crossing. Discrepancies were detected, and emphasized when the vehicle is within close distance from the receiver (pedestrian). However, the analysis indicated that these pose no hindrance to the study of vehicle–pedestrian interaction. Improvements to the method are identified and further developments are proposed.
Introduction:
Two aspects of noise annoyance were addressed in the present laboratory study: (1) the disturbance produced by vehicle pass-by noise while engaging in a challenging non-auditory task, and (2) the evaluative response elicited by the same sounds while imagining to relax at home in the absence of a primary activity.
Methods and material:
In Experiment 1, N = 29 participants were exposed to short (3-6 s) pass-by recordings presented at graded levels between 50 and 70 dB(A). Concurrent with each sound presentation, they performed a visual multiple-object tracking task, and subsequently rated the annoyance of the sounds on a VAS scale. In Experiment 2, N = 30 participants judged the sounds while imagining to relax, without such a cognitive task.
Results and discussion:
Annoyance was reduced when participants were engaged in the cognitively demanding task, in Experiment 1. Furthermore, when occupied with the task, annoyance slightly, but significantly increased with task load. Across both experiments, the magnitude of simultaneously recorded skin conductance responses in the first 1-4 s after the onset of stimulation increased significantly with sound pressure level. Annoyance ratings tended to be elevated across all sound levels, though significantly only in Experiment 2, in participants classified as noise sensitive based on a 52-item questionnaire.
Conclusions:
The results suggest that noise annoyance depends on the primary activity the listener is engaged in. They demonstrate that phasic skin conductance responses may serve as an objective correlate of the degree of annoyance experienced. Finally, noise sensitivity is once more shown to augment annoyance ratings in an additive fashion.
Green Infrastructure (GI) is defined as a network of natural and semi-natural areas that is strategically designed and managed to deliver a wide range of ecosystem services and to enhance human wellbeing. In Europe, the GI concept has been strongly related to the concepts of multifunctionality, climate change, and green growth, particularly in the last decade, leading to a research and policy agenda that varies greatly, targeting different audiences and topics. Here, we provide an up-to-date review of the key characteristics of GI research by focusing on the countries of the European Union. We consider the conceptualizations of GI, key research priorities, and thematic clusters within the existing literature. We demonstrate that the ambiguous definition of GI has generated a high diversity in research objectives and outputs. We also show that urban green spaces and ecosystems services are the most frequent topics and that more research is needed on the social aspects of GI. We suggest that an explicit incorporation of both nature conservation and social-environmental justice goals is essential for GI research to support sustainability transitions within and beyond the city.
The objective of this study was to determine changes in physiological indicators with time in different soundscapes and their correlation with the results of subjective restorative evaluation. Physiological indicators including the heart rate (HR), amplitude of the R-wave (ΔR), heart rate variability (HRV), electroencephalography alpha reactivity (α-EEG), electroencephalography beta reactivity (β-EEG), eye blink frequency (BF), respiratory frequency (RF), respiratory depth (RD), skin conductance level (SCL), and skin temperature (ST) were measured and analysed through audio-visual reduction in a laboratory, and the obtained data were compared with the answers to a perceived restorativeness soundscape scale survey. Through the analysis of variance by a repeated measures method, it was found that all physiological indicators (except for α-EEG) changed after one minute of measurements. Furthermore, BF and ST were not affected by the changes in the soundscape type, and the natural sound decreased the levels of HR, RF, and RD and increased the values of ΔR, HRV, α-EEG, and β-EEG. In addition, a canonical correlation analysis was performed to determine the correlation between the physiological indicators and subjective evaluation factors. The relationship between the physiological parameters measured within the first minute and results of subjective evaluation was relatively strong but insufficient for accurately interpreting the obtained physiological responses using only the subjective evaluation data.
Resonance Audio is an open source project designed for creating and controlling dynamic spatial sound in Virtual & Augmented Reality (VR/AR), gaming or video experiences. It also provides integrations with popular game development platforms and digital audio workstations (as a preview plugin). Resonance Audio binaural decoder is used in YouTube to provide binaural rendering of 360/VR videos. This paper describes the core sound spatialization algorithms used in Resonance Audio and can be treated as a companion to the Resonance Audio C++ / MATLAB library source code.
Audio-visual interactions play a significant role when humans perceive the environment. In this review paper, it is analysed how visible vegetation can be used to mitigate negative environmental noise perception with a focus on noise annoyance. Existing research has been analysed in view of three potentially explaining mechanisms namely source (in)visibility, the mere presence of visible green, and vegetation as a source of natural sounds. The source concealing potential vegetation has cannot fully explain reported findings. The restorative properties of visible vegetation seems the dominant mechanism. Visible natural features of good quality lead to sustained attention restoration and stress relief, counteracting negative outcomes of endured environmental noise exposure. There is strong evidence that noise annoyance experienced at home largely decreases when outdoor nature is present in the window pane. Additional support regarding the importance of such micro-restorative experiences is found by research at the working place, in hospital environments and at schools. Non-directly visible neighbourhood green shows to be positive as well, but with a smaller impact on noise perception. Natural sounds and especially bird songs are relaxing on theirselves, and support the restorative action of nature by suggesting nearby and vital nature. Based on rough quantitative estimates, the equivalent level reduction of (high quality)visible green from home could reach 10 dBA. This equivalent level reduction comes on top of the physical sound pressure level reduction one might obtain behind vegetation belts. At higher exposure levels, the improved noise perception one can get from vegetation is larger than at lower levels. The bulk of literature is concerned with road traffic noise, although scarce research suggests the applicability is much broader. Personal characteristics are expected to play a role in the interaction between noise perception and vegetation too.
Sound planning is not often included in the urban design process despite the well-known audio-visual interactions of human perception. A methodology to compare the overall appreciation of future renovation alternatives of urban public spaces using Virtual Reality Technology is proposed. This method is applied to assess the role of noise in the overall appreciation of a walk on a bridge crossing a highway. The auralization is a dynamic 3D surround based on B-format recordings (ambisonics), filtered by means of full-wave numerical calculations obtaining the sound field behind noise barriers along the bridge’s edge. Four different styles of visual street design including different noise barrier heights in combination with the 4 corresponding predicted sound fields were evaluated for their pleasantness by 71 normal-hearing participants on 4 separate days. Each day participants experienced all the visual environments with only one soundscape (to elude direct sound comparison) and anything related to sound was not mentioned in the first part of the experiment. Even in this non-focussed context, a statistically significant effect of the sound environment on the overall appreciation was found. In general, the pleasantness increases with traffic noise level reduction, but the visual design has a stronger impact. By mentioning the soundscape while introducing the evaluation, slightly lower (but statistically significantly different) pleasantness ratings were obtained. Instead of increasing noise barrier height, improving the visual design of a lower barrier seems more effective to increase pleasantness. Visual designs including vegetation strongly outperform others. The virtual experience was rated as immersive and realistic.
Today, urbanization presents a challenge to urban planning with regard to creating healthy living environments. The aim of this research is to gain further knowledge of the restorativeness of a best case urban and natural environment: that is a historic down town urban environment and forest environment located in an arboretum. The study has a cross-over design where 51 (N) female university students are exposed to the two Environments through both seated viewing and walking. A mixed method approach is used with both physiological measurements of blood pressure (BP) and heart rate variability (HRV) and psychological measurements of mood change and perceived restorativeness. The HRV results show no significant differences between the two environments, and both environments are found to be more physiologically restorative than being at the office or on the minibus. The results of the psychological measures indicate that the forest walk has a positive effect on mood, while the walk in the urban environment has no effect. The forest environment is also rated more highly with regard to perceived restorativeness than the urban environment. The results support the current research that shows natural environments as more restorative than urban environments. The study also adds to the ongoing debate on healthy urban planning by indicating that architectural and historical qualities may be associated with the physiological well-being of citizens.
Background:
While previous epidemiological studies report adverse effects of long-term noise exposure on cardiovascular health, the mechanisms responsible for these effects are unclear. We sought to elucidate the cardiovascular and stress response to short-term, low (31.5-125Hz) and high (500-2000Hz) frequency noise exposures.
Methods:
Healthy male (n=10) participants were monitored on multiple visits during no noise, low- or high-frequency noise exposure scenarios lasting 40min. Participants were fitted with an ambulatory electrocardiogram (ECG) and blood pressure measures and saliva samples were taken before, during and after noise exposures. ECGs were processed for measures of heart rate variability (HRV): high-frequency power (HF), low-frequency power (LF), the root of the mean squared difference between adjacent normal heart beats (N-N) intervals (RMSSD), and the standard deviation of N-N intervals (SDNN). Systolic blood pressure (SBP), diastolic blood pressure (DPB), and pulse were reported and saliva was analyzed for salivary cortisol and amylase. Multivariate mixed-effects linear regression models adjusted for age were used to identify statistically significant difference in outcomes by no noise, during noise or after noise exposure periods and whether this differed by noise frequency.
Results:
A total of 658, 205, and 122, HRV, saliva, and blood pressure measurements were performed over 41 person days. Reductions in HRV (LF and RMSSD) were observed during noise exposure (a reduction of 19% (-35,-3.5) and 9.1% (-17,-1.1), respectively). After adjusting for noise frequency, during low frequency noise exposure, HF, LF, and SDNN were reduced (a reduction of 32% (-57,-6.2), 34% (-52,-15), and 16% (-26,-6.1), respectively) and during high frequency noise exposure, a 21% (-39,-2.3) reduction in LF, as compared to during no noise exposure, was found. No significant (p<0.05) changes in blood pressure, salivary cortisol, or amylase were observed.
Conclusions:
These results suggest that exposure to noise, and in particular, to low-frequency noise, negatively impacts HRV. The frequencies of noise should be considered when evaluating the cardiovascular health impacts of exposure.
AARAE is a MATLAB-hosted environment for measurement and analysis of room acoustics and audio systems, designed to support education and research in audio and acoustics. While it already provides a wide range of test signals, and measurement, processing, and analysis methods, one of its main features is easy extensibility. Students new to signal processing (and MATLAB) can use it from its graphical user interface (without any need to write code), whereas more advanced students can develop implementations of pre-existing or novel measurement, processing and analysis algorithms using templates that allow quick integration of functions into the graphical user interface. AARAE was introduced into acoustics teaching at the University of Sydney in 2014, and it is used in both introductory and advanced units. While most of the code for the current version of AARAE was written by the authors, coursework students have contributed to functions in areas such as speech intelligibility, distortion, reverberation parameters and background noise rating. This paper illustrates how AARAE is used in teaching, highlighting some recent student projects in AARAE. It also illustrates how AARAE has been used to support research and research training.
This committee was appointed by the SPR Board to provide recommendations for publishing data on electrodermal activity (EDA). They are intended to be a stand-alone source for newcomers and experienced users. A short outline of principles for electrodermal measurement is given, and recommendations from an earlier report (Fowles et al., ) are incorporated. Three fundamental techniques of EDA recording are described: (1) endosomatic recording without the application of an external current, (2) exosomatic recording with direct current (the most widely applied methodology), and (3) exosomatic recording with alternating current-to date infrequently used but a promising future methodology. In addition to EDA recording in laboratories, ambulatory recording has become an emerging technique. Specific problems that come with this recording of EDA in the field are discussed, as are those emerging from recording EDA within a magnetic field (e.g., fMRI). Recommendations for the details that should be mentioned in publications of EDA methods and results are provided.
In the European Harmonoise project aiming at calculating the yearly day/evening/night weighted sound pressure levels from traffic noise the source model is completely separated from the propagation model. This paper presents the source model for road vehicles and discusses some aspects of it taking into account some new investigations carried out in the Nordic countries. The sound power levels of tyre/road noise and propulsion noise are given as equations as a function of frequency, speed and vehicle category. There are 5 different main vehicle categories each of which is subdivided into several sub categories. The sound power level is then distributed between point sources on different heights, each having a given vertical and horizontal directivity. These data refer to a reference condition defined by a constant speed, a specified road surface and a specified temperature. For conditions different from the reference conditions, corrections are given for air temperature, road surface, acceleration/deceleration and road surface wetness. In addition further corrections are possible, such as regional corrections to take into account systematic deviations from the conditions on which the reference equations are based. It is shown that the Harmonoise source model works quite well assuming that some regional corrections are taken into account.