New and refurbished school buildings in England and Wales need to comply with criteria for acoust... more New and refurbished school buildings in England and Wales need to comply with criteria for acoustics set out in Building Bulletin 93 (BB93). However, the acoustic design strategy to comply with Equality law and to ensure that 'people with disabilities, including those with hearing impairment, must not be placed at a disadvantage', is unclear and is complicated by other design factors and current funding constraints. This paper sets out to establish acoustic criteria for inclusion of children with special, hearing and communication needs (SHCN) in mainstream classrooms, using a 'reasonable adjustments' approach (which underpins Equality law). Listening disadvantage is quantified by each type of need according to a review of the speech perception studies evidence base. Holistic design and management of the classroom is considered, by quantifying the prevalence of children with SHCN; examining classroom management strategies and provision of assistive listening systems; accounting for teacher's voice protection; and considering other design aspirations (such as sustainability) alongside acoustic design objectives.
The ability of the Speech Transmission Index (STI) to predict speech intelligibility under noisy ... more The ability of the Speech Transmission Index (STI) to predict speech intelligibility under noisy conditions is highly dependent on the assumed spectrum of the speech signal. Examination of the literature showed that the long-term average speech spectrum of male talkers differs substantially from the speech spectrum recommended for STI calculations (IEC 60268-16). To explore these issues, the long-term average speech spectrum of forty male British English people was first measured, compared with the available literature and proposed for STI calculations. Then, using several voice alarm systems, the influence of the measured spectrum on STI calculations was assessed and comparisons made with the standard speech spectrum. The results showed significant STI differences under noisy conditions and considerable reductions in the required electrical power with the use of the new proposed male spectrum. This indicated that the current STI method could benefit from a revised speech spectrum.
The Journal of the Acoustical Society of America, 2019
An investigation has been carried out to examine the impact of different levels of classroom nois... more An investigation has been carried out to examine the impact of different levels of classroom noise on adolescents' performance on reading and vocabulary-learning tasks. A total of 976 English high school pupils (564 aged 11 to 13 years and 412 aged 14 to 16 years) completed reading tasks on laptop computers while exposed to different levels of classroom noise played through headphones. The tasks consisted of reading science texts, which were followed by multiple-choice questions probing comprehension and word learning. Number of questions attempted, times taken to read the texts and to answer questions were recorded, as well as correct answers to different types of question. The study consisted of two similar experiments, the first comparing performance in classroom noise at levels of 50 and 70 dB LAeq; and the second at levels of 50 and 64 dB LAeq. The results showed that the performance of all pupils was significantly negatively affected in the 70 dB LAeq condition, for the nu...
In the UK the document BB93 Acoustic Design of Schools provides design guidance for refurbished a... more In the UK the document BB93 Acoustic Design of Schools provides design guidance for refurbished and new classrooms. Traditionally, school acoustic design in the UK is concerned with the needs of the listener, rather than the voice ergonomics of the speaker. However, a recent survey undertaken by London South Bank University (LSBU) indicated that over 65% of the surveyed teachers had experienced voice problems during their career. This supports other studies suggesting that teachers have a significantly higher incidence of voice problems than the general population. In an effort to better understand the influence of classroom acoustic design on teachers' speech LSBU is undertaking measurements of teachers' voices in different classroom types. An Ambulatory Phonation Monitor (APM) is used to measure voice parameters (including the average speech sound level, fundamental frequency and phonation time) directly from the skin vibrations in the neck, thus eliminating the effects of other noise sources in the environment. The rooms involved are acoustically benchmarked separately to enable relationships between the voice data and acoustic parameters, such as unoccupied ambient noise levels and reverberation times, to be investigated. This paper will present the results of the field measurements to date, and discuss some of the findings.
This paper presents a review of research carried out in the past 40 years into various aspects of... more This paper presents a review of research carried out in the past 40 years into various aspects of noise in open plan classrooms. The emergence of open plan classroom design in response to progressive educational reforms is discussed. A limited amount of evidence of the effects of noise in open plan classrooms is presented. Surveys of both background and intrusive noise levels in open plan classrooms are summarized and compared. Differences between noise levels in open plan and enclosed classrooms are also considered. Recommended noise limits and acoustic design criteria for open plan classrooms are discussed, together with some current international standards. The paper concludes with a discussion of appropriate noise control measures to reduce noise and maximize speech intelligibility and speech privacy in open plan classrooms.
A poor acoustic environment in a school is known to negatively affect pupils&... more A poor acoustic environment in a school is known to negatively affect pupils' learning and achievement. This paper presents the design and findings of an online questionnaire survey of 11-16 year olds' impressions of their school's acoustic environment. A total of 2588 English secondary school pupils responded to the questionnaire. Factor analysis was used to identify variables which best characterized pupils' impressions of their school's acoustic environment. Four factors, corresponding to ease of hearing in school spaces, sensitivity to noise, the consequences of noise in the classroom, and annoyance to intermittent noise, accounted for 43% of the total variance in pupils' responses to the questionnaire. Analysis of the responses on these factors showed that pupils who reported additional learning needs such as hearing impairment, speaking English as an additional language or receiving learning support reported being significantly more affected by poor school acoustics than pupils reporting no additional learning needs. Older pupils were significantly more sensitive to noise annoyance and to the consequences of poor acoustical conditions on their learning and behaviour than younger pupils. Pupils attending suburban schools featuring cellular classrooms that were not exposed to a nearby noise sources were more positive about their school acoustics than pupils at schools with open plan classroom designs or attending schools that were exposed to external noise sources. The study demonstrates that adolescents are reliable judges of their school's acoustic environment, and have insight into the disruption to teaching and learning caused by poor listening conditions. Furthermore, pupils with additional learning needs are more at risk from the negative effects of poor school acoustics.
The Journal of the Acoustical Society of America, 2012
A recent project has investigated acoustical conditions in secondary (high) schools, and examined... more A recent project has investigated acoustical conditions in secondary (high) schools, and examined the effects of a poor acoustic environment on teaching and learning of 11- to 16-year-olds. Around 2600 pupils from suburban secondary schools in England responded to an online questionnaire concerning the acoustic environment in their schools. The questionnaire data highlighted the differential effects of noise reported by more vulnerable learners. A repeated measures experimental study involving 572 pupils examined reading performance under two different classroom noise simulations. Results revealed a complex pattern reflecting noise levels, time of testing and measure of reading performance used. Reading text while exposed to classroom noise of 70 dB resulted in quicker reading but less accuracy in measures of reading comprehension compared with performance in 50 dB. The data further suggested that the pupils were not processing the text as deeply as was evident from their reduced le...
The Journal of the Acoustical Society of America, 2011
This paper reports the results of a large scale, detailed acoustic survey of 42 open plan classro... more This paper reports the results of a large scale, detailed acoustic survey of 42 open plan classrooms of varying design in the UK each of which contained between 2 and 14 teaching areas or classbases. The objective survey procedure, which was designed specifically for use in open plan classrooms, is described. The acoustic measurements relating to speech intelligibility within a classbase, including ambient noise level, intrusive noise level, speech to noise ratio, speech transmission index, and reverberation time, are presented. The effects on speech intelligibility of critical physical design variables, such as the number of classbases within an open plan unit and the selection of acoustic finishes for control of reverberation, are examined. This analysis enables limitations of open plan classrooms to be discussed and acoustic design guidelines to be developed to ensure good listening conditions. The types of teaching activity to provide adequate acoustic conditions, plus the speech intelligibility requirements of younger children, are also discussed.
The Journal of the Acoustical Society of America, 1998
A laboratory study into the response of subjects to noises of varying intensity and frequency con... more A laboratory study into the response of subjects to noises of varying intensity and frequency content has been carried out. Eighty subjects ranging in age from approximately 20 to 70 yr were asked to rate sounds according to annoyance. The hearing levels of the subjects were tested using pure-tone audiometry. The annoyance ratings have been analyzed to investigate relationships between annoyance and spectral shape, and also to determine whether the annoyance responses are related to age or hearing acuity. Preliminary results suggest that there is a strong relationship between age and response to low-frequency sound, subjects over the age of 45 finding sounds with high levels of noise below 200 Hz significantly more annoying than younger subjects. However, the annoyance ratings of the older subjects do not appear to be related to hearing levels, suggesting that the response may be due to some other factor such as the association of the noise.
The Journal of the Acoustical Society of America, 1999
Commercial computer models are now generally available for the prediction of sound levels in indu... more Commercial computer models are now generally available for the prediction of sound levels in industrial workshops. Four models have been used in this investigation; including raynoise v3.0, ramsete v1.3, rayscad+v3.3, and fame v1.0. These models were validated in rooms with highly absorbent room surfaces using standard and Millington-based absorption coefficients. The rooms included hypothetical, performance, experimental, and industrial spaces. Measurement data were available for the six central octave bands. The results are presented for sound levels and reverberation time, in addition to which the execution time for each model is detailed. It was found that Millington-based absorption coefficients provided consistently more accurate predictions for each type of space than standard absorption coefficients.
The Journal of the Acoustical Society of America, 2008
While at school children are exposed to various types of noise including external, environmental ... more While at school children are exposed to various types of noise including external, environmental noise and noise generated within the classroom. Previous research has shown that noise has detrimental effects upon children’s performance at school, including reduced memory, motivation, and reading ability. In England and Wales, children’s academic performance is assessed using standardized tests of literacy, mathematics, and science. A study has been conducted to examine the impact, if any, of chronic exposure to external and internal noise on the test results of children aged 7 and 11 in London (UK) primary schools. External noise was found to have a significant negative impact upon performance, the effect being greater for the older children. The analysis suggested that children are particularly affected by the noise of individual external events. Test scores were also affected by internal classroom noise, background levels being significantly related to test results. Negative relat...
The Journal of the Acoustical Society of America, 1998
Ray tracing computer models have been developed for the prediction of the sound field and speech ... more Ray tracing computer models have been developed for the prediction of the sound field and speech intelligibility in long enclosures of any cross-sectional shape. The models for enclosures of circular and rectangular cross section are particularly suitable for the prediction of speech intelligibility in underground railway stations. The model for use in long enclosures of rectangular cross section has been validated using data measured in a real underground station in Hong Kong. Measurements of acoustics parameters including sound propagation, early decay time, clarity index C50, and center time D50 were made along the length of the platform, with a single source towards one end of the platform. The model correctly predicts the acoustic parameters, the predictions being particularly accurate at midfrequencies. In addition the speech transmission index is accurately predicted at all frequencies, especially in the far field of the source.
The Journal of the Acoustical Society of America, 2011
There is an increasing body of research into the acoustic environment of hospitals, which provide... more There is an increasing body of research into the acoustic environment of hospitals, which provides evidence of the detrimental effects of noise on the well being and comfort of patients and on staff, and of a significant rise in hospital noise levels in recent years. Much of this evidence has focused on specific areas of healthcare such as critical care and operating theatres, with comparatively few studies carried out within general inpatient wards and in UK hospitals. A project is currently being undertaken to investigate, through objective and subjective surveys, the noise climate and acoustic design within general inpatient facilities in the United Kingdom, and their influence on the acoustic comfort of patients and staff. Noise and acoustic surveys have been carried out in a range of inpatient wards, with corresponding questionnaire surveys of staff and patients. Three major UK hospitals have been involved in the study, and a substantial amount of data has been collected. Repor...
An image-source based computer model is presented for the prediction of sound distribution in non... more An image-source based computer model is presented for the prediction of sound distribution in non-diffuse fitted enclosed spaces, such as factories. The new model, CISM, was developed on the basis of the sound propagation predictions of the Ondet and Barbry RAYCUB model in laboratory and industrial spaces. CISM uses an optimum representation, based on the accuracy of the RAYCUB results, so that the prediction accuracy is maintained while run-time and data input requirements are reduced. The basis of CISM is described, and predictions for various configurations of a fitted laboratory space, an empty factory incorporating a single barrier and a theoretical space with absorptive patches are presented. For comparison, sound propagation measurements were obtained and RAYCUB derived models, RAYCUB-DIR and RAYCUB-DIR REDIR, were used to predict these sound levels. This work demonstrated that the CISM model is as accurate as the ray-tracing model RAYCUB in the described enclosed spaces. The advantages of the CISM model are a reduced run-time (for a typical factory, CISM is approximately ten times faster than RAYCUB-DIR) and reduced data input (CISM uses less than half the information required by RAYCUB-DIR).
New and refurbished school buildings in England and Wales need to comply with criteria for acoust... more New and refurbished school buildings in England and Wales need to comply with criteria for acoustics set out in Building Bulletin 93 (BB93). However, the acoustic design strategy to comply with Equality law and to ensure that 'people with disabilities, including those with hearing impairment, must not be placed at a disadvantage', is unclear and is complicated by other design factors and current funding constraints. This paper sets out to establish acoustic criteria for inclusion of children with special, hearing and communication needs (SHCN) in mainstream classrooms, using a 'reasonable adjustments' approach (which underpins Equality law). Listening disadvantage is quantified by each type of need according to a review of the speech perception studies evidence base. Holistic design and management of the classroom is considered, by quantifying the prevalence of children with SHCN; examining classroom management strategies and provision of assistive listening systems; accounting for teacher's voice protection; and considering other design aspirations (such as sustainability) alongside acoustic design objectives.
The ability of the Speech Transmission Index (STI) to predict speech intelligibility under noisy ... more The ability of the Speech Transmission Index (STI) to predict speech intelligibility under noisy conditions is highly dependent on the assumed spectrum of the speech signal. Examination of the literature showed that the long-term average speech spectrum of male talkers differs substantially from the speech spectrum recommended for STI calculations (IEC 60268-16). To explore these issues, the long-term average speech spectrum of forty male British English people was first measured, compared with the available literature and proposed for STI calculations. Then, using several voice alarm systems, the influence of the measured spectrum on STI calculations was assessed and comparisons made with the standard speech spectrum. The results showed significant STI differences under noisy conditions and considerable reductions in the required electrical power with the use of the new proposed male spectrum. This indicated that the current STI method could benefit from a revised speech spectrum.
The Journal of the Acoustical Society of America, 2019
An investigation has been carried out to examine the impact of different levels of classroom nois... more An investigation has been carried out to examine the impact of different levels of classroom noise on adolescents' performance on reading and vocabulary-learning tasks. A total of 976 English high school pupils (564 aged 11 to 13 years and 412 aged 14 to 16 years) completed reading tasks on laptop computers while exposed to different levels of classroom noise played through headphones. The tasks consisted of reading science texts, which were followed by multiple-choice questions probing comprehension and word learning. Number of questions attempted, times taken to read the texts and to answer questions were recorded, as well as correct answers to different types of question. The study consisted of two similar experiments, the first comparing performance in classroom noise at levels of 50 and 70 dB LAeq; and the second at levels of 50 and 64 dB LAeq. The results showed that the performance of all pupils was significantly negatively affected in the 70 dB LAeq condition, for the nu...
In the UK the document BB93 Acoustic Design of Schools provides design guidance for refurbished a... more In the UK the document BB93 Acoustic Design of Schools provides design guidance for refurbished and new classrooms. Traditionally, school acoustic design in the UK is concerned with the needs of the listener, rather than the voice ergonomics of the speaker. However, a recent survey undertaken by London South Bank University (LSBU) indicated that over 65% of the surveyed teachers had experienced voice problems during their career. This supports other studies suggesting that teachers have a significantly higher incidence of voice problems than the general population. In an effort to better understand the influence of classroom acoustic design on teachers' speech LSBU is undertaking measurements of teachers' voices in different classroom types. An Ambulatory Phonation Monitor (APM) is used to measure voice parameters (including the average speech sound level, fundamental frequency and phonation time) directly from the skin vibrations in the neck, thus eliminating the effects of other noise sources in the environment. The rooms involved are acoustically benchmarked separately to enable relationships between the voice data and acoustic parameters, such as unoccupied ambient noise levels and reverberation times, to be investigated. This paper will present the results of the field measurements to date, and discuss some of the findings.
This paper presents a review of research carried out in the past 40 years into various aspects of... more This paper presents a review of research carried out in the past 40 years into various aspects of noise in open plan classrooms. The emergence of open plan classroom design in response to progressive educational reforms is discussed. A limited amount of evidence of the effects of noise in open plan classrooms is presented. Surveys of both background and intrusive noise levels in open plan classrooms are summarized and compared. Differences between noise levels in open plan and enclosed classrooms are also considered. Recommended noise limits and acoustic design criteria for open plan classrooms are discussed, together with some current international standards. The paper concludes with a discussion of appropriate noise control measures to reduce noise and maximize speech intelligibility and speech privacy in open plan classrooms.
A poor acoustic environment in a school is known to negatively affect pupils&... more A poor acoustic environment in a school is known to negatively affect pupils' learning and achievement. This paper presents the design and findings of an online questionnaire survey of 11-16 year olds' impressions of their school's acoustic environment. A total of 2588 English secondary school pupils responded to the questionnaire. Factor analysis was used to identify variables which best characterized pupils' impressions of their school's acoustic environment. Four factors, corresponding to ease of hearing in school spaces, sensitivity to noise, the consequences of noise in the classroom, and annoyance to intermittent noise, accounted for 43% of the total variance in pupils' responses to the questionnaire. Analysis of the responses on these factors showed that pupils who reported additional learning needs such as hearing impairment, speaking English as an additional language or receiving learning support reported being significantly more affected by poor school acoustics than pupils reporting no additional learning needs. Older pupils were significantly more sensitive to noise annoyance and to the consequences of poor acoustical conditions on their learning and behaviour than younger pupils. Pupils attending suburban schools featuring cellular classrooms that were not exposed to a nearby noise sources were more positive about their school acoustics than pupils at schools with open plan classroom designs or attending schools that were exposed to external noise sources. The study demonstrates that adolescents are reliable judges of their school's acoustic environment, and have insight into the disruption to teaching and learning caused by poor listening conditions. Furthermore, pupils with additional learning needs are more at risk from the negative effects of poor school acoustics.
The Journal of the Acoustical Society of America, 2012
A recent project has investigated acoustical conditions in secondary (high) schools, and examined... more A recent project has investigated acoustical conditions in secondary (high) schools, and examined the effects of a poor acoustic environment on teaching and learning of 11- to 16-year-olds. Around 2600 pupils from suburban secondary schools in England responded to an online questionnaire concerning the acoustic environment in their schools. The questionnaire data highlighted the differential effects of noise reported by more vulnerable learners. A repeated measures experimental study involving 572 pupils examined reading performance under two different classroom noise simulations. Results revealed a complex pattern reflecting noise levels, time of testing and measure of reading performance used. Reading text while exposed to classroom noise of 70 dB resulted in quicker reading but less accuracy in measures of reading comprehension compared with performance in 50 dB. The data further suggested that the pupils were not processing the text as deeply as was evident from their reduced le...
The Journal of the Acoustical Society of America, 2011
This paper reports the results of a large scale, detailed acoustic survey of 42 open plan classro... more This paper reports the results of a large scale, detailed acoustic survey of 42 open plan classrooms of varying design in the UK each of which contained between 2 and 14 teaching areas or classbases. The objective survey procedure, which was designed specifically for use in open plan classrooms, is described. The acoustic measurements relating to speech intelligibility within a classbase, including ambient noise level, intrusive noise level, speech to noise ratio, speech transmission index, and reverberation time, are presented. The effects on speech intelligibility of critical physical design variables, such as the number of classbases within an open plan unit and the selection of acoustic finishes for control of reverberation, are examined. This analysis enables limitations of open plan classrooms to be discussed and acoustic design guidelines to be developed to ensure good listening conditions. The types of teaching activity to provide adequate acoustic conditions, plus the speech intelligibility requirements of younger children, are also discussed.
The Journal of the Acoustical Society of America, 1998
A laboratory study into the response of subjects to noises of varying intensity and frequency con... more A laboratory study into the response of subjects to noises of varying intensity and frequency content has been carried out. Eighty subjects ranging in age from approximately 20 to 70 yr were asked to rate sounds according to annoyance. The hearing levels of the subjects were tested using pure-tone audiometry. The annoyance ratings have been analyzed to investigate relationships between annoyance and spectral shape, and also to determine whether the annoyance responses are related to age or hearing acuity. Preliminary results suggest that there is a strong relationship between age and response to low-frequency sound, subjects over the age of 45 finding sounds with high levels of noise below 200 Hz significantly more annoying than younger subjects. However, the annoyance ratings of the older subjects do not appear to be related to hearing levels, suggesting that the response may be due to some other factor such as the association of the noise.
The Journal of the Acoustical Society of America, 1999
Commercial computer models are now generally available for the prediction of sound levels in indu... more Commercial computer models are now generally available for the prediction of sound levels in industrial workshops. Four models have been used in this investigation; including raynoise v3.0, ramsete v1.3, rayscad+v3.3, and fame v1.0. These models were validated in rooms with highly absorbent room surfaces using standard and Millington-based absorption coefficients. The rooms included hypothetical, performance, experimental, and industrial spaces. Measurement data were available for the six central octave bands. The results are presented for sound levels and reverberation time, in addition to which the execution time for each model is detailed. It was found that Millington-based absorption coefficients provided consistently more accurate predictions for each type of space than standard absorption coefficients.
The Journal of the Acoustical Society of America, 2008
While at school children are exposed to various types of noise including external, environmental ... more While at school children are exposed to various types of noise including external, environmental noise and noise generated within the classroom. Previous research has shown that noise has detrimental effects upon children’s performance at school, including reduced memory, motivation, and reading ability. In England and Wales, children’s academic performance is assessed using standardized tests of literacy, mathematics, and science. A study has been conducted to examine the impact, if any, of chronic exposure to external and internal noise on the test results of children aged 7 and 11 in London (UK) primary schools. External noise was found to have a significant negative impact upon performance, the effect being greater for the older children. The analysis suggested that children are particularly affected by the noise of individual external events. Test scores were also affected by internal classroom noise, background levels being significantly related to test results. Negative relat...
The Journal of the Acoustical Society of America, 1998
Ray tracing computer models have been developed for the prediction of the sound field and speech ... more Ray tracing computer models have been developed for the prediction of the sound field and speech intelligibility in long enclosures of any cross-sectional shape. The models for enclosures of circular and rectangular cross section are particularly suitable for the prediction of speech intelligibility in underground railway stations. The model for use in long enclosures of rectangular cross section has been validated using data measured in a real underground station in Hong Kong. Measurements of acoustics parameters including sound propagation, early decay time, clarity index C50, and center time D50 were made along the length of the platform, with a single source towards one end of the platform. The model correctly predicts the acoustic parameters, the predictions being particularly accurate at midfrequencies. In addition the speech transmission index is accurately predicted at all frequencies, especially in the far field of the source.
The Journal of the Acoustical Society of America, 2011
There is an increasing body of research into the acoustic environment of hospitals, which provide... more There is an increasing body of research into the acoustic environment of hospitals, which provides evidence of the detrimental effects of noise on the well being and comfort of patients and on staff, and of a significant rise in hospital noise levels in recent years. Much of this evidence has focused on specific areas of healthcare such as critical care and operating theatres, with comparatively few studies carried out within general inpatient wards and in UK hospitals. A project is currently being undertaken to investigate, through objective and subjective surveys, the noise climate and acoustic design within general inpatient facilities in the United Kingdom, and their influence on the acoustic comfort of patients and staff. Noise and acoustic surveys have been carried out in a range of inpatient wards, with corresponding questionnaire surveys of staff and patients. Three major UK hospitals have been involved in the study, and a substantial amount of data has been collected. Repor...
An image-source based computer model is presented for the prediction of sound distribution in non... more An image-source based computer model is presented for the prediction of sound distribution in non-diffuse fitted enclosed spaces, such as factories. The new model, CISM, was developed on the basis of the sound propagation predictions of the Ondet and Barbry RAYCUB model in laboratory and industrial spaces. CISM uses an optimum representation, based on the accuracy of the RAYCUB results, so that the prediction accuracy is maintained while run-time and data input requirements are reduced. The basis of CISM is described, and predictions for various configurations of a fitted laboratory space, an empty factory incorporating a single barrier and a theoretical space with absorptive patches are presented. For comparison, sound propagation measurements were obtained and RAYCUB derived models, RAYCUB-DIR and RAYCUB-DIR REDIR, were used to predict these sound levels. This work demonstrated that the CISM model is as accurate as the ray-tracing model RAYCUB in the described enclosed spaces. The advantages of the CISM model are a reduced run-time (for a typical factory, CISM is approximately ten times faster than RAYCUB-DIR) and reduced data input (CISM uses less than half the information required by RAYCUB-DIR).
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