J S Bradley's research while affiliated with National Research Council Canada and other places
What is this page?
This page lists the scientific contributions of an author, who either does not have a ResearchGate profile, or has not yet added these contributions to their profile.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
Publications (93)
ISO 3382-1 describes a number of objective room acoustics parameters that are generally accepted as useful for rating some specific aspects of concert hall sound fields. They include measures of decay times, energy ratios, measures of sound strength and several quantities related to the spatial aspects of sound fields. In most cases there are detai...
This article discusses the relationship between the two metrics, and their suitability for use in any type of space, including spaces not fitting the definition of either open or closed. The E2638 method provides a rating of the average performance of a closed room - without any assumptions as to talker location - to each of a number of listener po...
In this paper, preliminary results are presented for the objective and subjective ratings of the impact sound insulation provided by light-weight wood-framed floor ceiling assemblies, but in this paper, additional results specific to the heavy impact sources are discussed., On présente dans ce document les résultats préliminaires d?évaluations obje...
This research was jointly funded by the Royal Canadian Mounted Police (RCMP), Public Works and Government Services Canada (PWGSC) and the National Research Council, Institute for Research in Construction (NRC-IRC).
For each of a series of full-scale floor-ceiling assemblies, standard impact measurements were made with the sources defined in ISO 10140 including the tapping machine, the modified tapping machine, and the heavy/soft impact source (rubber ball), dropped from various heights. Additionally, sound recordings were made of the sounds generated by the b...
The sound attenuating properties of walls can be measured in laboratory tests of sound transmission loss versus frequency. These values are often reduced to the single value of the Sound Transmission Class, STC, rating to simplify the rank ordering of the sound insulating properties of walls. However, the average Transmission loss, TL(avg), is now...
This report presents extensive laboratory measurements to evaluate a new speech security quick test intended to provide accurate estimates of the results of the full speech security test (ASTM E2638-08).
The Journal of the Acoustical Society of America 127(2), 1165 (2010) DOI: http://doi.org/10.1121/1.3277151
Speech levels were measured in a large number of meetings and meeting rooms to better understand their influence on the speech privacy of closed meeting rooms. The effects of room size and number of occupants on average speech levels, for meetings with and without sound amplification, were investigated. The characteristics of the statistical variat...
This paper describes a newsyste of speech privacy criteria in terms of Speech Privacy Class (SPC) values. SPC values can be used to specify the required speech privacy for new construction or to assess the speech privacy of ex-isting closed rooms. The ASTM E2638 measurement standard defines SPC as the sum of the measured average noise level at the...
Although open offices with conventional cubicle workstations are very common, it is still difficult to achieve acceptable speech privacy even in situations where the acoustical design is seriously considered. Speech privacy criteria were initially given in terms of the Articulation Index (AI) but should now be converted to be in terms of the newer...
This project developed design and measurement tools to facilitate the attainment of better speech privacy in open-plan offices. The research investigated the relationships among speech privacy measures, and between these measures and the geometrical and acoustical properties of open-plan office workstations. The paper presents speech privacy criter...
A procedure was developed for assessing the sound security of rooms that need to be ?speech secure' so that it is difficult or impossible for eavesdroppers outside the room to understand or even hear speech from a meeting room. The procedure is capable of detecting weaknesses in individual components of the sound insulation of a room and accounts f...
This series of papers presents results from recent major projects on building acoustics at the National Research Council. In each case, major reports providing more detail on the projects are listed at the end of the brief abstracts. The reports are available from the NRC/IRC website http://irc.nrc-cnrc.gc.ca/ircpubs , using the code (e.g. - RR-170...
It is well known that good acoustical design should optimise room acoustics and minimise unwanted noise so that effective speech-to-noise ratios are maximised in classrooms. However, the common experience of difficult speech communication in many rooms is evidence that many problems remain. A review of the literature shows that reported noise level...
Subjective ratings of the audibility, annoyance, and loudness of music and speech sounds transmitted through 20 different simulated walls were used to identify better single number ratings of airborne sound insulation. The first part of this research considered standard measures such as the sound transmission class the weighted sound reduction inde...
This paper reports new measurements of the intelligibility of speech in conditions representative of elementary school classrooms. The speech test material was binaurally recorded in simulated classroom conditions and played back to subjects over headphones. Subjects included grade 1, 3, and 6 students (6, 8, and 11 year olds) as well as adults. Re...
This report presents extensive laboratory measurements to evaluate a new speech security quick test intended to provide accurate estimates of the results of the full speech security test (ASTM E2638-08). Ce rapport fait état de mesures en laboratoire exhaustives qui ont été réalisées dans le but d'évaluer un nouvel essai rapide de la confidentialit...
This guide describes a framework for interpreting, assessing, and rating the speech privacy and speech security of closed meeting rooms and offices. The document provides a concise technical overview of the underlying concepts and defines categories for rating and setting criteria. This guide also contains a detailed measurement procedure to be fol...
This report describes the results of a focussed study of the spatial and temporal effects of room acoustics on the intelligibility of speech including speech transmitted from an adjacent room. The purpose of the work was to gain an initial understanding of how these effects influence the speech privacy of enclosed rooms. On décrit dans ce rapport l...
Speech privacy class (SPC) has been introduced to rate the speech privacy for meeting rooms. The speech privacy system need to detect the weakness in individual components of the sound insulation of an office or meeting rooms. The uniform-weighted signal-to-noise ratio can be used to determine the audibility and intelligibility of transmitted speec...
This is the second of two papers describing the results of acoustical measurements and speech intelligibility tests in elementary school classrooms. The intelligibility tests were performed in 41 classrooms in 12 different schools evenly divided among grades 1, 3, and 6 students (nominally 6, 8, and 11 year olds). Speech intelligibility tests were...
This paper reports on an evaluation of ratings of the sound insulation of simulated walls in terms of the intelligibility of speech transmitted through the walls. Subjects listened to speech modified to simulate transmission through 20 different walls with a wide range of sound insulation ratings, with constant ambient noise. The subjects' mean spe...
This report gives the results of a number of case studies using the SPMSoft speech privacy measurement software to demonstrate its usefulness for evaluating acoustical conditions in open-plan offices and to illustrate the characteristics of many typical open-plan office acoustics problems. Ce rapport fournit les résultats d'un certain nombre d'étud...
This report documents various tests to evaluate the performance of SPMSoft. This includes validation tests of each component of the measurements and evaluation of the repeatability of the results. Further sections give help for interpreting the measurement results and advice for optimizing the quality of each measurement. Ce rapport documente diver...
This report describes the results of evaluations of airborne sound insulation measures in terms of the annoyance and loudness of transmitted speech and music sounds. Subjects rated sounds simulating transmission through 20 different walls with a wide range of sound transmission characteristics. The evaluated measures included the standard Sound Tra...
The SPMSoft computer program makes it possible to conveniently measure speech privacy between locations in open-plan offices. The program outputs test signals and measures the response to them as well as measuring ambient noise levels. From these data the program calculates objective measures of the speech privacy between the source and receiver lo...
The intelligibility of speech recordings made in rooms and other spaces is affected by factors such as reverberation, background noise, the distance between the speaker and the microphone, and the properties of the microphone system. This paper presents results of tests evaluating the intelligibility of speech recordings made with a variety of micr...
This paper describes new listening tests to evaluate various airborne sound insulation ratings in terms of the intelligibility of transmitted speech. In these experiments listeners heard test sentences played, at a fixed level, through 20 different simulated walls in the presence of a constant low-level ambient noise. Dans ce document, on décrit de...
This report gives the results of new listening tests to evaluate various airborne sound insulation ratings in terms of the intelligibility of transmitted speech. These subjective evaluations of sound insulation ratings are a first experiment of several intended to validate existing sound insulation ratings and investigate possible improvements. In...
This report summarizes measurements made on a test wall that was modified to include a variety of defects. The severity and detectability of the known defects was investigated. Not all defects were severe enough to cause a leak that was any worse than the natural variation of sound insulation across the wall. Other defects were marginally severe en...
This report brings together several research studies to explain how to design meeting rooms to be speech secure and how to measure the degree of speech security of existing rooms. Speech security refers to a high level of speech privacy and corresponds to conditions in which it is difficult to understand speech from an adjacent room. For a high deg...
A new speech privacy measurement procedure accurately indicates the degree of speech privacy at individual listening locations outside of a closed room, including near localized weak spots. To investigate the importance of various defects (such as penetrations, electrical outlets), they were introduced into a test wall dividing two reverberation ro...
This report gives new experimental results from a project to develop a new approach to predicting and measuring the architectural speech security of meeting rooms. The new results are intended to experimentally validate two components of the previous work. The first part of this report presents results that evaluate the validity of previous listeni...
A meeting room is said to be completely speech secure when persons outside the room are not able to understand conversations from within the room, or in more extreme cases are not able to detect any speech sounds from the room. This report describes measurements of sound transmission from meeting rooms to adjacent spaces to evaluate procedures for...
The term ?speech security' is used to describe very high levels of speech privacy sometimes required for closed meeting rooms. A room is said to be completely speech secure when persons outside the room are not able to understand conversations from within the meeting room, or in more extreme cases are not able to detect any speech sounds from the m...
Detailed acoustical measurements were made in 41 active elementary school classrooms near Ottawa, Canada to obtain more representative and more accurate indications of the acoustical quality of conditions for speech communication during actual teaching activities. This study found: a mean speech-to-noise ratio in active classrooms of 11dBA, reverbe...
This paper summarizes new subjective studies to better define conditions required for acceptable speech privacy and acceptable noise levels in conventional open-plan offices. Achieving both of these goals will lead to satisfactory acoustic comfort in open office environments. Ambient noise levels of about 45 dBA are judged to be most preferred in t...
As part of a larger project concerning the design and operation of open plan offices, a field study was conducted to determine the effects of open-plan office design on the indoor environment and on occupant satisfaction with that environment. Measurements were made in nine buildings in six cities; six buildings were in Canada, and three in the US;...
The issue of architectural speech security is concerned with the degree to which rooms in buildings are acoustically isolated. For example, a conversation occurring within a room being intelligible to persons outside the room is indicative of a problem. To rate the degree to which transmitted speech is intelligible?or even audible?an objective meas...
Application of the ISO3382 standard can lead to the acquisition of large amounts of data describing conditions in a hall. The data could include the values of a number of measures at 6 or more octave band frequencies and for many combinations of source and receiver location. This paper discusses and gives examples of using this data to find importa...
Architectural speech security refers to the inability of eavesdroppers to hear speech sounds from nearby meeting rooms and offices where confidential material is being discussed. (Here ?architectural' refers to the security provided by the building structure and associated building systems such as ventilation systems). The audibility of speech soun...
This paper summarizes the results of new acoustical measurements for both occupied and unoccupied conditions and speech recognition tests in 43 classrooms of grade 1, 3 and 6 students. Speech and noise levels were measured during a regular teaching activity as well as during the speech tests. Room acoustics measurements were obtained from impulse r...
This paper describes the process and problems of developing a new measure of architectural speech security. Such a measure is required to more accurately rate the probability of a listener outside a room being able to overhear conversations from within the room. Previous work has considered various levels of speech privacy, where some speech is int...
This paper presents the results of new studies based on speech intelligibility tests in simulated sound fields and analyses of impulse response measurements in rooms used for speech communication. The speech intelligibility test results confirm the importance of early reflections for achieving good conditions for speech in rooms. The addition of ea...
This report provides the results of over 100 laboratory measurements of the sound transmission loss of building façade components. These included various wall and roof constructions along with some windows and a number of tests to evaluate the effects of vents on sound insulation. The current work is a major component of the IBANA project (Insulati...
The primary goal of the acoustical design of conventional open-plan offices (cubicle style) is to achieve an acceptable level of acoustical or speech privacy. That is, we would like to make it more difficult for occupants to hear and understand speech sounds from adjacent workstations. We can therefore measure speech privacy by measuring the intell...
As part of a larger project concerning the design and operation of open plan offices, a field study was conducted to determine the effects of open-plan office design on the indoor environment and on occupant satisfaction with that environment. Measurements were made in nine buildings in six cities; six buildings were in Canada, and three in the US;...
This paper describes the development of a mathematical model of sound propagation between adjacent workstations in an open-plan office. The model is valid for adjacent rectangular workstations consisting of small enclosures made up of partial-height screens or panels. The new model adds the effects of side and back panels to the primary effect of t...
In part I of this paper a general model was developed of sound propagation between adjacent rectangular workstations in a conventional open-plan office. In this paper, the new model is used to investigate the importance of various office design parameters on calculated speech privacy. The additional effects of the side and back panels of complete w...
Improved acoustical privacy is the principal goal of the acoustical design of open plan offices. As the replacement of the Articulation Index (AI), the Speech Intelligibility Index (SII) can be used as a single-number measure of the speech privacy in open-plan offices. In this paper, a mathematical model of the speech propagation over single screen...
In open-plan offices, single screen barriers are widely used to separate individual workplaces as a means of improving acoustical privacy. In this paper, a general model for calculating the insertion loss of a single screen barrier in the presence of a floor and a ceiling is developed using the image source technique. In addition to the acoustical...
This letter corrects typographical errors in two previously published regression equations relating measured speech intelligibility scores and useful-to-detrimental sound ratios. The implications of one of these corrections on a more recent paper are shown to be small. A new and more generally applicable relationship is presented that was derived f...
The Cost-Effective Open-Plan Environments (COPE) project plan identified a need to develop relationships between acoustic conditions in open-plan offices and occupant satisfaction with those conditions. Two experiments were designed to meet this need. In each experiment, participants hired from a staffing agency for one day experienced 15 different...
This report compares measurements of the sound insulation of various constructions of a test house, exposed to aircraft noise at Ottawa Airport, with predictions from laboratory measurements of the same constructions. Further analyses investigated the major sources of the differences between laboratory and field measurements and corrections were de...
This report compares measurements of the sound insulation of various constructions of a test house, exposed to aircraft noise at Ottawa Airport, with predictions from laboratory measurements of the same constructions. Further analyses investigated the major sources of the differences between laboratory and field measurements and corrections were de...
This article reports the results of a series of measurements of the sound transmission loss of exterior wood-stud walls. The tested walls were representative of contemporary constructions used in climates where significant thermal insulation is required. The measurements included important low-frequency bands to make it possible to correctly charac...
A review of the effects of ambient noise and reverberation on speech intelligibility in classrooms has been completed because of the long-standing lack of agreement on preferred acoustical criteria for unconstrained speech accessibility and communication in educational facilities. An overwhelming body of evidence has been collected to suggest that...
In North America, both single-unit and multiple housing is frequently built using wood stud construction. The overall sound insulation of many common wood stud walls is limited by excess low frequency sound transmission and indoor aircraft noise levels are dominated by low frequency sound. A study to develop improved methods for determining the sou...
Although it is often standard procedure to use resilient channels to improve the sound transmission loss of a wall or floor system, there was no simple model of their performance, nor a quantitative understanding of the important properties of the resilient channels. This paper provides a simple model for explaining the effects of adding resilient...
New experiments have investigated the effect on perceived listener envelopment of late-arriving sound from above and behind the listener using simulated sound fields. In all cases, the listener envelopment was found to be principally related to the cosine-squared weighted late-arriving sound energy. The late lateral sound level measure, that incorp...
IBANA-Calc is software that was developed to calculate the effect of sound insulation against aircraft noise and to provide the user with indoor noise levels for different outdoor aircraft noises and building constructions. The software is intended to be both more accurate and more convenient than previous approaches1 that have used look-up tables...
This report presents the results of an extensive series of measurements of sound propagation between pairs of mock-up workstations. Inter-workstation propagation measurements were repeated for 104 variations of the workstation configuration to determine the effect of each of the major design variables. The measurements were made to aid in developin...
This paper describes six new experiments involving subjective ratings of the listener envelopment, LEV, and the apparent source width, ASW, of simulated sound fields. Previous work has identified LEV and ASW as the principal components of spatial impression in concert halls and has shown that ASW is primarily influenced by the level of early latera...
Algorithms that have been proposed for predicting speech intelligibility based on the articulation loss of consonants AL(cons) are revisited. The simplest algorithm, known as the architectural form of the Peutz equation, is discussed and rederived using a technique to find forms of empirical equations. it is shown that other Peutz algorithms, which...
The sound insulation of building façade components is most accurately measured in laboratory tests involving pairs of reverberation chambers. This paper reports on the problems of converting from laboratory to field measurements of sound insulation, and is part of a larger project to develop new data and procedures for predicting the sound insulati...
This report provides the results of over 100 laboratory measurements of the sound transmission loss of building façade components. These included various wall and roof constructions along with some windows and a number of tests to evaluate the effects of vents on sound insulation. The current work is a major component of the IBANA project (Insulati...
Speech intelligibility in rooms is influenced by room acoustics effects and by the signal-to-noise ratio (S/N) of the speech and ambient noise. Several measures such as useful-to-detrimental sound ratios and the speech transmission index predict the combined effects of both types of factors. These measures were evaluated relative to speech intellig...
C-50 is an early-to-late arriving sound ratio used to assess the influence of room acoustics on the clarity and intelligibility of speech. A just noticeable difference in C-50 values was determined for speech sounds in simulated sound fields. Over a range of C-50 values from -3 to +9dB, representing most situations in rooms for speech, a just notic...
A comparative study of speech intelligibility metrics that take into account sound refections in the room and the background noise has been developed based on the assumption of a d iffuse sound field in the room Under this assumption the room reverberant response results in an exponential decay with a damping constant inversely proportional to the...
Speech intelligibility in rooms is determined by both room acoustics characteristics as well as speech-to-noise ratios. These two types of effects are combined in measures such as useful-to-detrimental sound ratios which are directly related to speech intelligibility. This paper reports investigations of optimum acoustical conditions for classrooms...
This paper gives an overview of three topics related to sound insulation in buildings. The first project included laboratory and field measurements of sound insulation against aircraft noise. As well as various technical papers, the project produced software to help in the design of adequate sound insulation. In a second project, re-analysis of sur...
This paper summarizes information from tests made to determine speech security thresholds for closed offices based on three thresholds: 1) threshold of audibility, where the speech sounds are just audible; 2) threshold of cadence, where the overheard sounds are just recognizable as speech possessing rhythm or cadence; and 3) threshold of intelligib...
A simple wood frame test house was constructed at Ottawa Airport and aircraft noises were recorded at locations in each of two test rooms and outdoors. The construction of the test house was systematically varied by changing interior surfaces and by adding windows. For some tests interior masking walls were added to limit propagation to predominant...
Airborne sound insulation ratings can be evaluated in terms of their correlation with various subjective ratings of sound insulation. This paper considers sound insulation ratings in terms of the intelligibility of transmitted speech because speech is a common type of disturbing sound and because speech intelligibility tests can provide accurate su...
The current trends in office design - putting everyone in smaller, open-plan spaces, with low partitions - might lead to adverse physical conditions and dissatisfaction for employees. NRC's Cost-effective Open-Plan Environments project combined the expertise of psychologists, acousticians, engineers, and architects in conducting experimental and fi...
IBANA-Calc is software that was developed to calculate the effect of sound insulation against aircraft noise and to provide the user with indoor noise levels for different outdoor aircraft noises and building constructions. The software is intended to be both more accurate and more convenient than previous approaches1 that have used look-up tables...
This paper reports the results of tests made to assess the intelligibility of speech recordings and a STIPA modulated noise stimulus made with several microphone systems placed in various locations in a range of controlled test spaces. The intelligibility of the test speech recordings was determined by a subjective listening test. STIPA was determi...
Speech privacy is related to how difficult it is for a listener to hear or understand speech. For a closed room, conversations occurring within are to be private from listeners outside the room, in the adjoining spaces. The degree of audibility or intelligibility of the speech at the listening positions will depend on the sound insulation provided...
![Figure 1: Results of the laboratory studies of Marshall [3], Elliott...](profile/Hiroshi-Sato-9/publication/44066715/figure/fig1/AS:669539331231760@1536642024432/Results-of-the-laboratory-studies-of-Marshall-3-Elliott-1-and-previous-in-situ-tests_Q320.jpg)
This paper reports on testing done to more accurately define the needs of young listeners in actual classroom conditions. improve knowledge about how signal-to-noise ratios (S/N) needs vary with the age of listeners. The WIPI (Word Intelligibility by Picture Identification) test was used in classrooms to assess the word recognition performance of g...
Citations
... Thus, physical work environment has a negative effect on nurses not only on the level of stress, but also on the ability to perform. Furthermore, this result is similar with (Newsham et al., 2004), physical environment in which people work affects both job performance and job satisfaction. In this present study, the nurse with greater physical environment stressors such as excessive noise, poor lighting and so on, have lower performance. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/272466794774550-1441972554642_Q64/Jennifer-Veitch-2.jpg)
... * n_kellati@hotmail.com Nous procédons dans cette partie par la mesure de l'isolement acoustique D du liège compact, définit comme étant la soustraction entre le niveau sonore émis du côté haut parleur, et celui transmis du côté sonomètre [3][4][5]. En suite nous terminons par l'identification du coefficient de transmission. ...
... A hundred lab-based measurements were collected from Lund University in Sweden and the National Research Council (NRC-CNRC) [21] in Canada. The data consists of air-borne sound insulation curves that concern various lightweight façade structures in one-third-octave bands (50 Hz to 5 kHz). ...
... The sound transmission through sandwich gypsum constructions has always been a grey area of research for its interior applications for noise abatement and control. There have been many studies (Warnock, 1985;1993;1998;1997;Bradley, Birta, 2001;Bradley, Gover, 2011;Guillen et al.., 2008;Uris et al., 1998;Halliwell et al., 1998;Quirt et al., 1995;Roozen et al., 2015) reported so far, especially those reported by National Research Council (NRC), Canada, that focus on the enhancement of sound transmission loss of sandwich gypsum constructions and the use of masonry walls in conjunction with the dry wall technology. Thus, the parametric sensitivity of various factors controlling the sound insulation is instrumental in designing sandwich constructions for optimizing the sound insulation characteristics (Garg et al., 2013a;2013b;2013c;2014a). ...
... It was suggested that a RT range from 0.5 s to 0.7 s was optimum, and a RT range from 0.4 s to 0.8 s was acceptable for good speech intelligibility in classrooms [5]. Other studies support these findings and recommend 0.4-0.5 s RT as optimum [16,26,27]. Nijs & Rychtáriková (2011) recommends 0. 6 RT in classrooms about 200 m 3 to achieve good intelligibility [28]. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/755630226808833-1557167693536_Q64/Sylvio-Bistafa.jpg)
... Papers [20,21] present the values of intelligibility threshold in the rooms for SNRuni32, depending on the necessary level of speech information privacy. Three levels were considered: "intelligibility in free space", "intelligibility in the premises" and "intelligibility of the fact of talk", which correspond to values -11 dB, -16 dB and -22 dB [21]. ...
... In these spaces more recently developed acoustical criteria such as the C50, which is based on the ratio of early to late arriving energy, find significant application and investiga tion. [3], [4], [5] An investigative analysis of the C50 for the typical gymna sium space was performed using a commercially available ray-tracing software package. The results indicate negative values o f C50. ...
Reference: Reverberation in gymnasia
![[object Object]](https://i1.rgstatic.net/ii/profile.image/279327557079044-1443608287270_Q64/Rebecca-Reich.jpg)
... Existing methods do not specifically address the problem of information leaking between zones and may lead to the ability of users to deduce what content is being reproduced in other zones, e.g. in private teleconference meetings. Good speech privacy requires that the leaked speech signal is not intelligible [19], [20]. Although research has shown how to synthesise and reproduce wideband speech soundfields in multiple zones, state-of-the-art methods still lack the acoustic contrast between zones to provide speech privacy [2], [3], [7], [8]. ...
... The relationship speech transmission index, speech intelligibility and speech privacy is shown in Table 4.1.1. For an good speech privacy, a speech transmission index equal to or smaller than 0.2 is advised (158). In order to evaluate the speech intelligibility between two adjacent working areas, whether or not separated by a sound barrier, this study uses the Cope-Calc validated computerprogram of the National Research Council Canada (159) based on the Wang and Bradley model (160). ...
... Early decay time (EDT) is considered to be better adapted to the perception of reverberance [20], but it is a less "global" measure. It may vary with source-receiver distance depending on the main reflections in the room, and repeatability problems have been reported for measurement positions close to the sound source [21]. The just-noticeable difference (JND) for reverberation time metrics in the literature ranges from 5 to 24 per cent [20,[22][23][24]. ...
