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Proc. 135th ASA and 16th ICA: 01 June 1998, Seattle

This report presents the measurement results of acoustical tests in 10 different atrium spaces. These measurements were made as part of the acoustical component of a multidisciplinary project to study the indoor environment of atrium spaces attached to office buildings. The acoustical component included the measurements reported here as well as computer simulation studies to be reported elsewhere. The main purpose of this report is to present a summary of the measurement results to characterize typical acousticalconditions in a wide variety of atrium spaces. Detailed analyses of these results will be left to future publications.

A recent review of aircraft noise issues in Canada was conducted by the National Research Council for Transport Canada [1,2,3]. This review was quite broad in scope but identified the need for improved design procedures for the sound insulation of buildings against aircraft noise. Aircraft noise levels have been considerably reduced at the source over the past 30 years. The result of this effort is the introduction of quieter Chapter 3 commercial jet aircraft. In a few years the change over to these quieter aircraft will be complete and further large reductions at the source are not likely to occur. After noise reduction at the source, the most frequently recommended solution for reducing the negative impact of aircraft noise in buildings near airports, is increased sound insulation. In Canada a widely accepted design procedure has been in use since the mid 1970s [11]. Unfortunately it is now largely obsolete. It is based on the spectra of older aircraft types and does not include sound insulation data for commonly used modern Canadian exterior façade construction types. It is quite cumbersome to use and has never been systematically validated by measurements in a range of buildings near airports This report is the first part of a project to produce a modern design procedure for insulating buildings against aircraft noise. It is intended to be a comprehensive review of current knowledge on the sound insulation of buildings. It discusses what is known concerning the basic principles, measurement procedures and measurement results from previously published studies related to building sound insulation. It is intended that this will provide a basis for planning the next part of this project: to develop a new, up to date, more accurate and easier to use design procedure.

Aussi disponible en français: L'IRC améliore sa salle de réverbération

Proceedings of 16th International Congress on Acoustics and 135th American Acoustical Society Meeting: 20 June 1998, Seattle, Washington

Noise problems are one of the leading sources of dissatisfaction expressed in post occupancy evaluations. Unwanted noise is annoying and distracting, and can lead to a reduction in overall job satisfaction and task productivity, and further reinforces the private office as a corporate status symbol. The acoustical design of open office space to achieve a productive work environment is a delicate balance between blocking, absorbing and masking unwanted speech sounds and controlling excessive ambient noise. While open office space is the focus of this review, there are other related types of spaces that make up the office environment and that each have their own special acoustical needs. Meeting rooms must have very low ambient noise levels and optimum room acoustics to maximize the efficiency of communication. For closed offices it is necessary to pay attention to the construction details of partitions so that an adequate level of acoustical privacy is obtained., COPE Seminar: 17 October 1997, Ottawa, Ontario

The most important characteristic of any concert hall must be the sound that it delivers to the listener. While the acoustics of a hall are unlikely to make a good orchestra sound bad, a well designed auditorium can provide a truly memorable experience. Yet the Boston Symphony Hall, which opened in 1900, was the first to be designed with the science of acoustics in mind.

Although gypsum board is probably the most common interior surface treatment in use in the United States and Canada today, the sound-absorbing properties of many common wall constructions are not well known. The results of sound absorption tests performed on several gypsum board cavity walls are reported. A calculation model was developed that accurately fits the measured data. The increased low-frequency absorption is related to themass-air-mass resonance of the wall construction. The model also includes a residual high frequency sound absorption component related to the properties of the exposed surface of the wall. This model can now be used to conveniently predict the sound absorption of other similar gypsum board wall constructions and to design walls with some specified minimal amount of low-frequency absorption.

Also published in Canadian Acoustics, v. 25, no. 3, September 1997, p. 21., Acoustics Week in Canada 1997: 08 October 1997, Windsor, Ontario

This is the second of three reports containing the results of an NEF validation study for Transport Canada. Summaries of the other two reports are included in Appendix 2 of this report. Airports can be both an asset and a liability to nearby communities. Much of the negative impact of an airport is directly due to aircraft noise. Thus, the trade-offs between the costs and the benefits that an airport provides are very strongly related to the details of exposures to aircraft noise., Ceci est le deuxième de trois (3) rapports qui contiennent les résultats d'une étude de validation de prévisions d'ambiance sonore (NEF) menée pour le compte de Transports Canada. L'annexe 2 de ce rapport contient les résumés des deux autres. Pour les collectivités qui se trouvent à proximité immédiate d'un aéroport, celui-ci peut représenter soit un atout, soit un handicap. À cet égard, l'incidence négative des aéroports est en grande partie attribuable directement aux bruits produits par les aéronefs. Ainsi, les compromis entre coûts et avantages d'un aéroport sont très étroitement liés aux degrés d'exposition aux bruits des aéronefs.

This is the summary of the final report of a project to evaluate the validity of the NEF measure of aircraft noise. This final report is intended to directly respond to the specific requirements of the original proposal. A database of references and two technical reports have already been sent to Transport Canada as part of this project. Summaries of the previous technical reports are included in the Introduction of this report. The highlights of this final report include:General RecommendationsUpgrade (and provide ongoing support for) the continuing development of the NEF_1.7 program.Establish and publish noise criteria for all major Canadian airports in terms of NEF values and supplementary single event noise criteria.Undertake a major Canadian survey of response to aircraft noise to include: isolated single event type problems, various smaller airport situations, tests of various time-of-day weightings, evaluation of the long term effectiveness of additional home insulation, and to provide a comprehensive calibration of the NEF measure.Support updating of the CMHC document on new housing and aircraft noise.Consider adopting an A-weighted NEF measure.Encourage all levels of government to follow a uniform national approach to the management of airport noise in Canada.

This is the first of three reports containing the results of an NEF validation study for Transport Canada. Summaries of the other two reports are included in Appendix 2 of this report. The NEF_1.7 program is a critical part of the management of airport noise in Canada, and it is extremely important that its validityand accuracy be as good as is reasonably possible. The use of millions of dollars worth of land near airports is determined by the noise level contours from this program. Similarly, the acceptability of land nearairports for residential use is determined from the calculated noise contours produced by the NEF_1.7 program. The analyses of this report suggest that improving the detail of the flight path description anddeveloping a more correct excess ground attenuation calculation procedure would considerably improve the NEF_1.7 program. It is therefore essential that the required continuing development of the NEF_1.7 program receive the necessary financial and technical support. The analyses of this report were focused on the errors associated with predicting noise levels around airports. The related problems of determining acceptable noise level limits and the practical application of these limits will be considered in a second report. These two reports will form the technical background for a final report evaluating the use of theNEF measure to quantify airport noise levels near Canadian airports., Ceci est le premier de trois (3) rapports contenant les résultats d'une étude de validation des indices NEF pour le compte de Transports Canada. L'annexe 2 aux présentes contient les résumés des deux autres rapports. Les analyses de ce rapport ont été centrées sur les erreurs associées à la prédiction des niveaux de bruit à proximité des aéroports. Les problèmes connexes de la détermination des limites acceptables de bruit et de l'application pratique de ces limites seront pris en compte dans le cadre du deuxième rapport. Ces deux rapports formeront l'acquis technique du rapport final faisant l'évaluation de l'utilisation des mesures des indices NEF en vue de quantifier les niveaux de bruit aéroportuaires, à proximité d'aéroports canadiens.

Disponible aussi tôt que possible Le présent document est un résumé du rapport final d'un projet visant à évaluer la validité de la mesure NEF du bruit des aéronefs. Le rapport final donne suite aux exigences particulières du projet original. Une base de données regroupant les références bibliographiques, ainsi que deux rapports techniques ont déjà été envoyés à Transports Canada dans le cadre du projet. Vous trouverez dans l'introduction du présent rapport des résumés des rapports techniques antérieurs. Voici les principaux éléments du présent rapport :Recommandations généralesPerfectionner le programme NEF_1.7 (assurer le soutien continu du développement du programme).Déterminer et publier les critères de bruit se rapportant aux aéroports principaux du Canada en valeurs NEF, de même que les critères de bruit se rapportant aux épisodes de bruit isolés additionnels.Entreprendre une étude à l'échelle nationale sur la réaction des gens face au bruit des aéronefs, dans laquelle on traitera des points suivants : problèmes découlant des épisodes de bruit isolés, situations variées se produisant dans les petits aéroports, essais de différentes méthodes de pondération par heures du jour, évaluation de l'efficacité à long terme de l'isolation additionnelle des maisons, etc. Cette étude permettra l'étalonnage complet de la mesure NEF.Soutenir la mise à jour du document de la SCHL sur les nouveaux secteurs résidentiels et le bruit des aéronefs.Considérer l'adoption d'une mesure NEF pondérée A.Encourager tous les paliers de gouvernement à suivre une démarche nationale uniforme en ce qui a trait à la gestion des bruits que présentent les aéroports au Canada.

Presented at Acoustics Week in Canada, Oct. 1996., Acoustics Week in Canada: 1996-10, Calgary, Alta, Canada

Proceedings of Inter-Noise '96: 01 August 1996, Liverpool, England

This paper discusses the practical problems of optimizing the decay range in room acoustics measurements using MLS techniques. It includes a wide range of measurements to demonstrate the influence of various factors and concludes with a step-by-step approach to optimizing such measurements.

In his pioneering work on spaciousness, Barron3 found that strong reflections arriving at the listener from the side and shortly after the direct sound increased the apparent width of the source. The recognition of the importance of such strong early lateral reflections helped to explain the success of narrow shoebox-shaped concert halls such as those in Vienna and Boston. This discovery led to a revolution in concert hall design and has been a key focus of research in concert hall acoustics for the past 25 years. Many newer halls have been designed with large reflecting panels to provide strong early lateral reflections. These new halls have generally been quite successful, but it is possible for such designs to produce an excess of clarity and a sense of insufficient reverberance.

This report presents the results of comparisons of 23 different room acoustics measurement systems. The round robin comparisons were obtained by shipping a digital reverberator to each measurement group. Three preset settings of the reverberator were used to represent three different standard rooms that each group measured. Comparisons were made for octave band values of eight different room acoustics quantities as well as RASTI values.

This paper reports the results of subjective studies to determine objective predictors of perceivedlistener envelopment in concert halls. Subjects, seated in an anechoic room, were exposed tosimulated sound fields that were expected to have varied listener envelopment. As independentvariables: the reverberation time the early-to-late sound ratio, the overall sound level, and theangular distribution of the late-arriving sound levels were varied. All of these factors hadstatistically significant effects on perceived listener envelopment. The results indicate, however, that the angular distribution of the late arriving sound and the overall level would have the largest effects in real concert halls. Thus listener envelopment depends on having strong lateral reflections arriving at the listener 80 ms or more after the direct sound. Several objective measures correlated significantly with listener envelopment. However, a new measure, the late lateral sound level, as measured using a figure-of-eight microphone, was found to be both conceptually simple and a very good predictor of the perceived listener envelopment of the sound fields in this experiment.

This paper describes the new indoor environment research facility recently constructed at the Institute for Research in Construction, National Research Council Canada. This facility allows full-scale testing and physical modelling of office space lighting, thermal comfort, indoor air quality, airflow and contaminant-flow patterns, ventilation, acoustical characteristics, and occupants' reactions to these parameters. The facility consists of a test room, approximately, 12 m by 7 m by 2.74 m high, with adjustable interior partitions. The test area can range in size from a single large open area, to four identical single-office sized test rooms., 16th AIVC Annual Conference on Implementing the Results of Ventilation Research: 19 September 1995, Palm Springs, CA., U.S.A.

15th ICA, June 1, 1995, Trondheim

This paper describes a series of experiments which confirm that there ate at least two distinct dimensions to spatial impression, apparent source width (ASW) and listener envelopment (LEV), and that each is related to different aspects of the sound field.

15th International Congress on Acoustics, June 1995, Trondheim, Norway

A series of experiments were conducted to evaluates several acoustical measures as predictors of subjective judgments. Subjects were asked to rank binaurally reproduced sound fields in terms of loudness, clarity, reverberance bass, treble, envelopment, apparent source width, and overall preference. The binaural impulse responses were measured in several North American concert halls and were chosen so as to cover as broad a range as possible of RT, EDT, C80, G, IACC, and LF values. The results of these tests were then correlated with the various octave-band objective measures to find the best predictor of each subjective parameter. New objective quantities were found that are correlated with loudness, clarity, bass, and treble judgments. The relative importance of the various subjective parameters to the overall preference of these sound fields was also examined.

This paper reports the results of an initial experiment to evaluate the additional annoyance caused by varying amounts of low frequency rumble sounds from heating, ventilating, and air conditioning (HVAC) systems. HVAC noises were simulated with various levels of low-frequency sound and varying amounts of amplitude modulation of the low-frequency components. Subjects listened to the test sounds over headphones and adjusted the level of the test sounds to be equally annoying as a fixed neutral reference sound. The results indicated that annoyance is influenced by both the level and the amplitude modulation of the simulated HVAC rumble sounds. A procedure that incorporates these two factors is suggested for predicting the additional annoyance of HVAC sounds containing rumble.

Presented at Acoustics Week in Canada, Ottawa, Ont., Canada, Oct. 17-21, 1994

Presented at Acoustics Week in Canada, Ottawa, Ont., Canada, Oct. 17-21, 1994

Presented at Acoustics Week in Canada, Ottawa, Ont., Canada, Oct. 17-21, 1994

Proceedings Sabine Centennial Symposium: 01 June 1994, Cambridge, Mass., U.S.A.

About a h,undred years have passed since Sabine proposed his measure of reverberation time as apredictor of the acoustic quality of a concert hall. Since then, as a result of extensive research and ourability to make increasingly precise acoustical measurements, researchers have proposed many otherobjective measures as predictors of a concert hall's acoustic quality. In this paper, a series of experimentswere conducted to evaluate the suitability of several acoustical measures as predictors of subjectivejudgements. Subjects were asked to rank binaurally reproduced sound fields in terms of reverberance,clarity, loudness, envelopment, treble, bass, apparent source width, and overall preference. The binauralimpulse responses were measured in several North American concert halls and were chosen so as to cover asbroad a range as possible with respect to RT60, EDT, C80, G, IACC and LF values. The results of thesetests were then correlated with the various objective measures on an octave band basis to find the bestpredictor of each subjective parameter. The relative importance of the various subjective parameters to theoverall preference of these sound fields was also examined., Proceedings Sabine Centennial Symposium: 01 June 1994, Cambridge, Mass., U.S.A.

American Acoustical Society, Sabine Centennial Conference Proceedings: 05 June 1994, Cambridge, MA, USA

Presented at Acoustics Week in Canada, Ottawa, Ontario, Canada Oct. 17-21, 1994, Presented at Acoustics Week in Canada: 17 October 1994, Ottawa, Ont., Canada

Aussi disponible in francais: Amélioration de l' acoustique d'une cathédrale

Inter-Noise '94: 29 August 1994, Yokahama, Japan