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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, reverberation times from 0.3 to 0.6 s that were not related to noise levels, and the effects of children on acoustical conditions., International Congress on Acoustics 2004: 04 April 2004, Kyoto, Japan

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 intelligibility, where the overheard speech is just intelligible. Subjects listened to a large number of sentences representing a wide range of acoustical conditions, and repeated the words they could understand, or stated whether or not they could identify the speech or its cadence., 18th International Congress on Acoustics: 04 April 2004, Kyoto, Japan

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 sounds from meeting rooms will depend on how loud the transmitted speech sounds are relative to the existing ambient noise levels. It is therefore necessary to know the values of typical speech levels generated in meeting rooms and the levels of typical ambient noises in spaces near meeting rooms. This report presents the results of extensive measurements of speech sounds in meeting rooms and ambient noises in nearby spaces. The probability of various speech and noise levels occurring is reported and recommendations are made for using these results in calculations to estimate the architectural speech security of particular offices and meeting rooms., La notion d'isolement acoustique architectural des entretiens équivaut à l'inaptitude de toute personne indiscrète à entendre les conversations se déroulant dans des salles de réunion et des bureaux avoisinants, pendant que l'on y discute de sujets de nature confidentielle. (Le terme « architectural » ici renvoie à la structure du bâtiment et aux systèmes de bâtiment connexes, comme les systèmes de ventilation, et à la protection que ces structure et systèmes peuvent procurer.) L'audibilité des bruits de conversation des salles de réunion dépend de l'intensité sonore des bruits de conversation transmis par rapport aux niveaux de bruit ambiants existants. Il est par conséquent nécessaire de connaître les valeurs des niveaux sonores types de la parole qui est générée dans les salles de réunion et les niveaux types de bruit ambiant dans les espaces situés près de ces salles. Ce rapport présente les résultats de mesures poussées des bruits de conversation dans les salles de réunion et des bruits ambiants dans les espaces avoisinants. La probabilité de l'occurrence de divers niveaux de parole et de bruit est ici relatée, et des recommandations sont fournies quant à l'utilisation de ces résultats pour fin de calculs visant l'estimation de l'isolement acoustique architectural de certains types de bureaux et de salles de réunion.

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; three were federal buildings, two were provincial buildings, and four were private-sector (high-tech) buildings. A total of 779 employees and their workstations were included in the data set. During a workstation visit, research staff conducted detailed measurements of ventilation, temperature, noise, lighting, and descriptive characteristics of the workstation during a 10-minute period. At the same time, the occupant completed a 27-item questionnaire on a handheld computer concerning their satisfaction with the workplace. The satisfaction data are analysed in other project reports, this report is concerned only with relationships between the physical variables., Dans le cadre d'un projet plus vaste concernant la conception et l'exploitation des bureaux en espace fonctionnel, on a mené une étude sur le terrain dans le but de déterminer les effets de la conception de bureaux à aires ouvertes sur l'environnement intérieur et la satisfaction des occupants face à cet environnement. On a effectué des mesures dans neuf bâtiments situés dans six villes; six des bâtiments se trouvaient au Canada et les trois autres, aux États-Unis; trois d'entre eux étaient des immeubles fédéraux, deux bâtiments étaient des immeubles provinciaux et les quatre autres, des bâtiments du secteur privé (de haute technologie). L'ensemble de données incluait en tout 773 employés et leur poste de travail. Au cours de la visite d'un poste de travail, le personnel de recherche procédait à des mesures détaillées de la ventilation, de la température, du bruit, de l'éclairage et des caractéristiques descriptives du poste pendant 10 minutes. Au même moment, l'occupant répondait sur un assistant numérique à 27 questions concernant la mesure dans laquelle il était satisfait de son poste de travail. Les données relatives à la satisfaction sont analysées dans d'autres rapports de projet; le présent rapport concerne uniquement les relations entre les variables physiques.

only, Canadian Acoustical Conference, 1 October 2003, Edmonton

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 intelligible [1]. However, speech security usually implies that none of the overheard speech is intelligible, or in some cases it is not even audible., Article also published in Canadian Acoustics, v. 31, no. 4, Dec. 2003, pp. 24-25

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 intelligibility of speech sounds from adjacent workstations., Le but premier de la conception acoustique des bureaux à aire ouverte conventionnels (style poste de travail modulaire) est de fournir un niveau acceptable d'intimité acoustique ou d'intimité des conversations. En bref, rendre difficile la compréhension de nos conversations par les occupants des postes de travail voisins. Mesurer l'intimité des conversations, c'est en sorte mesurer l'intelligibilité des sons qui nous parviennent des postes de travail voisins.

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 Speech Intelligibility Index (SII). Other new work gives us a better indication of likely speech levels in open plan office environments. These are essential for accurate estimates of speech privacy criteria. A recently published model of sound propagation between workstations is used to demonstrate the importance of design parameters on the resulting speech privacy and to derive minimum acoustical requirements for open office ceilings., Inter-Noise 2003: 25 August 2003, Seogwipo, Korea

Aussi disponible en français: De meilleures conditions acoustiques pour des employés plus satisfaits

This paper uses a previously developed model of sound propagation in conventional open plan offices to explore the influence of each parameter of the office design on the expected speech privacy in the office. The ceiling absorption, the height of partial height panels and the workstation plan size are shown to be most important. However, it is not possible to achieve 'acceptable' speech privacy if all design parameters do not have near to optimum values. A successful open office should also include an optimum masking sound spectrum and an office etiquette that encourages talking at lower voice levels.

A recent study looking at the role of sound insulation in mitigating aircraft noise has resulted in a new, more accurate design tool that allows users to compare the effectiveness of different building constructions in providing sound attenuation. The study has also yielded a better understanding of how to insulate buildings against outdoor noise. IRC researchers made extensive laboratory measurements of the sound insulation of building envelope components, including various wall and roof constructions, as well as windows and doors. Further experiments in a test house at Ottawa airport explored the complexities of sound propagation into a building exposed to aircraft noise.

Good acoustical design should optimise room acoustics and minimise unwanted noise so that effective speech-to-noise ratios are maximised in rooms for speech. Although reported noise levels in classrooms almost always exceed ideal criteria, these results may be questioned because it is difficult to measure the speech and noise levels that actually occur during speech. Many criteria are based on studies that show a poor understanding of room acoustics and tend to prescribe more absorptive environments because they ignore the positive effects of early reflections. The more stringent requirements for various special needs groups of listeners are much less well defined. We still design rooms in terms of reverberation time that only indirectly relates to critical room acoustics details and even this we cannot do accurately. This paper reviews recent studies of these problems and outlines remaining research needs., WESPAC: Western Pacific Acoustics Conference, 7 April 2003, Melbourne, Australia

This report compares measured and predicted indoor sound levels in buildings exposed to aircraft noise. Predictions were made using the IBANA-Calc software that was developed to make it easy and convenient to calculate indoor sound levels in buildings exposed to aircraft noise. This report is therefore a further validation of the IBANA-Calc software and an exploration of some of the details of the predictions and the differences between laboratory and field measurements of sound insulation. The work is the final component of the IBANA project (Insulating Buildings Against Noise from Aircraft) that included: (a) laboratory measurements of the sound transmission loss of building envelope components, (b) field measurements of a varied constructions of a test house at Ottawa Airport and (c) development of the IBANA-Calc software. Measurements reported here were made using multi-track recordings of indoor andoutdoor sound levels in buildings near Vancouver and Toronto Airports. These included new homes near Toronto Airport, an older home near Vancouver Airport and offices in a Vancouver Airport building. The sites were not ideal simple cases but included various complicating factors that made the predictions more challenging.

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 levels in classrooms almost always exceed ideal criteria, but these results may be questioned because it is difficult to measure the speech and noise levels that occur during actual speech. Many criteria are based on studies that show a poor understanding of room acoustics and tend to prescribe more absorptive environments ignoring the positive effects of early reflections. The more stringent requirements for various special needs groups such as younger listeners are much less well defined. We still design rooms in terms of reverberation time that only indirectly relates to critical room acoustics details and even this we cannot do accurately. This paper will review recent studies that have attempted to solve some of these problems and will outline key remaining research needs., Proceedings of XX Meeting of SOBRAC (Brazilian Acoustical Association): 21 October 2002, Rio de Janeiro

This paper considers the problem of measuring incident aircraft noise when validating predictions of indoor aircraft noise levels from free-field outdoor levels such as those obtained from airport noise level contours. Both ASTM E966 and ISO 140/V indicate that the incident outdoor noise for measurements of the sound insulation of building facades can be obtained using microphones positioned at the building façade. Measurements of the incident aircraft noise at the façade and in the free field indicate that this can lead to large differences from simple expectations. This paper presents the results of measurements of aircraft passbys showing the variations in the incident sound levels as a function of the aircraft elevation. These were related to the effects of diffraction from the building façade as well as to the effects of ground reflections. This interpretation was confirmed both mathematically and using a scale model façade in an anechoic room. It was concluded that more general and easier to interpret estimates of incident sound levels can be obtained from free field measurements than from façade-mounted microphone measurements., Inter-Noise 2002: 19 August 2002, Dearborn, MI., U.S.A.

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 predominantly through one of the exterior walls of each room. The measured octave band noise reductions were compared to predicted values from laboratory tests of exactly the same constructions. Ground reflections and internal flanking paths were found to influence results. When these were taken into account the mean prediction error was 3.1 dBA for walls without windows and only 0.5 dBA for walls with windows. The remaining errors were mostly due to differences in low frequency resonances between the laboratory and the field situations., Inter-Noise 2002: 19 August 2002, Dearborn, MI., U.S.A.

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 simulated ventilation noises in combination with simulated telephone conversations, and provided ratings of their satisfaction with each noise condition. Each exposure consisted of a 15-minute period of work on memory and clerical tasks, followed by 2-3 minutes to complete a questionnaire concerning satisfaction, speech intelligibility, and the characteristics of the noise. This report concerns only the questionnaire data. Memory and clerical task performance in relation to the noise conditions will be reported separately. · Experiment 1: Noise spectrum effects on satisfaction. In this experiment subjects experienced 15 different simulated noise spectra in combination with the speech from simulated telephone conversations. · Experiment 2: Noise spectrum and noise level effects on satisfaction. This experiment used three noise spectra at each of five A-weighted noise levels, for a total of 15 different noise conditions in combination with the speech from simulated telephone conversations., Was also published as a conference paper at the 63rd Annual Convention of the Canadian Psychological Association held in Vancouver, B.C., on May 30-June 1, 2002

Aussi disponible en français: En bref - Un logiciel pour concevoir des bâtiments mieux isolés contre les bruits d'avion

Le présent rapport établit une comparaison des mesures de l'isolation acoustique d'une habitationd'essai soumise au bruit d'aéronefs à l'aéroport d'Ottawa et ce, pour différentes configurations. Ilcomprend également les prévisions établies à partir des mesures en laboratoire pour les mêmesconfigurations. Des analyses additionnelles ont ensuite porté sur les principales sources d'écartsentre les mesures en laboratoire et celles sur le terrain et des correctifs ont été élaborés pour lelogiciel d'isolation acoustique IBANA-Calc. Des formes du spectre de sources visant les typesd'aéronefs modernes ont aussi été élaborées pour le logiciel.La Structure d'essai de l'aéroport d'Ottawa (SEAO) est une structure à ossature de bois simple,représentative des techniques de construction types au Canada, comportant deux piècesprincipales soumises au bruit des aéronefs. La construction a été modifiée méthodiquement defaçon à intégrer des différences dans les murs et les plafonds, à ajouter des fenêtres ainsi quedifférents orifices de ventilation. Pour certains essais, des murs isolateurs ont été ajoutés danschaque pièce pour simplifier la situation et faire en sorte que le son ne se transmetteprincipalement que par l'un des murs extérieurs. Pour chacune des configurations, le bruit del'aéronef au décollage a été enregistré à l'extérieur, dans le champ libre et sur la façade dubâtiment, ainsi qu'à l'intérieur, à trois endroits dans chacune des deux pièces d'essai.

Cet article traite des spécifications acoustiques permettant une communication orale détendue et précise, ainsi que des critères de conception pour des salles de taille différente. Nous abordons certains aspects propres à des types de salles et des auditoires particuliers.

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 developed for the IBANA-Calc sound insulation software. Source spectrum shapes for modern aircraft types were also developed for this software. The Ottawa Airport Test Structure (OATS) was a simple wood frame structure, representative of typical Canadian construction techniques, with two main rooms exposed to the noise from passing aircraft. The construction was systematically changed to include differences in wall and ceiling constructions, the addition of windows, and also the addition of various vents. In some tests, additional masking walls were added insideeach room to simplify the situation so that sound transmission was predominantly through one of the outside walls. For each construction, the noise of departing aircraft was recorded outside in the free field and at the building façade as well as inside at 3 positions in each of the 2 test rooms.

This Update explains the acoustical requirements conducive to relaxed and accurate speech communication in rooms and gives design criteria for a wide range of room sizes. Some special issues for particular types of rooms and special groups of listeners are discussed.

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 and single number ratings of sound insulation to provide this information.The program was written as part of the IBANA (Insulation Buildings Against Noise from Aircraft) project and includes a large database of new sound transmission loss data of building façade elements as well as a database of aircraft noise spectra both collected as part of the project.It is intended that the software be used as a convenient tool to aid in the calculation of the effect of various sound insulation designs. The software is not an expert system and as such the user must have some expertise in the area of noise control engineering.

Acceptable values for party wall sound insulation were derived from the grouped subjective ratings obtained from a field survey of 600 subjects and the airborne sound insulation of their 300 party walls. The subjects lived in both row housing and multi-floor apartment buildings in three different Canadian cities and included both owners and renters. The survey results clearly demonstrate that residents are influenced by the amount of sound insulation between them and their neighbour and that the effects are largely independent of the type of housing or type of tenure. Spontaneous responses show increasing negative ratings of their buildings with decreasing sound insulation. Residents with poor sound insulation are more likely to want to move, to be awakened by noises and to have trouble falling asleep due to noises, as well as to think that their neighbours are less considerate. Directly elicited responses are used to determine STC 55 as a realistic goal for acceptable sound insulation and STC 60 as a more ideal goal that would practically eliminate negative effects of neighbour's noises., Inter-Noise 2001: 27 August 2001, The Hague, Netherlands

Dans cet article, on présente les résultats de l'analyse des données globales d'un sondage sur l'insonorisation des murs séparant les logements dans les immeubles d'habitation, réalisé dans trois villes canadiennes. Dans le cadre de cette étude, on a procédé, en personne, à des entrevues détaillées dans l'appartement des sujets, ainsi qu'à des mesures complètes, dans chaque appartement, de l'atténuation du bruit par les murs mitoyens et des mesures du bruit ambiant dans chaque appartement, et ce, sur une période de 24 heures., Canadian Acoustics Conference issue: 01 October 2001, Aliston, Ontario

Dans cet article, on décrit les mesures de l'effet de la masse des couches de revêtement, de la taille et de l'espacement des colombages, des séparations structurales et de la présence d'isolant dans les cavités sur l'affaiblissement acoustique des murs extérieurs à ossature de bois. Au Canada, les constructions modernes sont généralement plus hermétiques que les immeubles plus anciens, et leurs murs, plus épais, contiennent plus d'isolant thermique. Cette recherche sur les propriétés acoustiques des murs modernes fait partie d'un projet plus important portant sur l'évaluation des éléments des façades extérieures et sur l'élaboration d'une procédure informatique permettant de concevoir l'insonorisation des immeubles exposés aux bruits des aéronefs. Nous avons effectué des mesures conformément à la méthode E90 de l'ASTM, mais dans une gamme de fréquences allant de 50 à 5 kHz. Nous avons classé l'efficacité globale des murs à l'aide de la classe de transmissions extérieur-intérieur (OITC) de l'ASTM., Canadian Acoustics Conference Issue: 01 October 2001, Aliston, Ontario

Aussi disponible en français: L'IRC met au point un logiciel pour une meilleure isolation contre les bruits d'avion : Article also published in Solplan Review, March 2001, p. 18.

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 developing and validating a model of speech propagation between rectangular workstations in open plan offices. This work is one of the technical building blocks of the acoustical aspects of the COPE project (Cost-effective Open Plan Environments). The COPE project will consider the optimisation of the complete open office indoor environment. The report includes detailed measurements of inter-workstation sound attenuations in 1/3 octave frequency bands. However, the results are presented in terms of the single number Speech Intelligibility Index (SII) rating that is a good indicator of the expected speech privacy of each configuration. (SII is a weighted speech-to-noise ratio varying between 0 and 1. A value of 1 represents near perfect intelligibility and a value of 0 represents near perfect privacy).

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 (Insulating Buildings Against Noise from Aircraft). The complete IBANA project includes both laboratory and field measurements of building façade sound insulation as well as the creation of computer software to permit the convenient use of this data to design the exterior soundinsulation of buildings against aircraft noise. Tests were performed according to the ASTM E90 procedure that involves building the test partition in an opening between two reverberation chambers. The results givemeasures of the sound insulation of each façade component for randomly incident sound energy. The OITC (Outdoor-Indoor Transmission Class) was used to give a singlenumber rating of the sound insulation of each construction against aircraft noise. Many of the tests were carried out as a number of mini-series in which a particular component was varied but other details of the construction were not varied. For examplethe effects of different exterior wall cladding were investigated on the same basic wall construction.

The objective of the present work is to obtain the reverberation time and the maximum background-noise level for classrooms for best speech intelligibility conditions. These will be derived by comparing the results provided by three speech intelligibility metrics, under the assumption of a diffuse sound field with ideal exponential decays.

Proceedings of Acoustics Week in Canada 2000: 28 September 2000, Sherbrooke, Québec

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 insulation of buildings against aircraft noise., Proceedings of Inter Noise 2000: 27 August 2000, Nice, France

In this paper the RNC methodology is tested using annoyance data that has been collected in a study of annoyance caused by HVAC system noise. Results of the RNC methodology are compared to the psycho-acoustical evaluations of the annoyance study. The comparisons reveal that the RNC curves and methodology provide improved characterization of noise in rooms.

Presented at Acoustics Week in Canada, held October 18, 1999 in Victoria, B.C.

Presented at Acoustics Week in Canada, held October 18, 1999 in Victoria, B.C.

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 reverberation time. This allows analytical formulas to be obtained for each of the speech intelligibility metrics considered in this study, and provides a common basis for this comparative study. These formulas were applied to three sizes of a rectangular shaped classroom, inside which the sound source was a human voice without amplification. The background noise was taken into account in these formulas by a noise-to-signal ratio written in terms of the noise level and the vocaloutput level at 1 meter in front of the talker. Correlation between the metrics and speechintelligibility obtained by the respective authors, using different types of articulation testing material, are also presented and applied to the classrooms under study. Relationships between some of the speech intelligibility metrics were also established. It was then possible to verify that for each noise-to-signal ratio, the value of each speech intelligibility metric is maximized for a specific reverberation time, which was considered to be the optimum reverberation time. It was found that for very quiet classrooms, the optimum reverberation time predicted by all the speech intelligibility metrics is 0.1 - 0.3 s. Where there is more ambient noise, optimum reverberation times are larger. The range of reverberation times for 100 % speech intelligibility was found to vary somewhat among the dzfferent speech intelligibility metrics. This is due to different articulation tests used, and also due to a rather arbitrary way of establishing cut-off values forthe metrics that use a subjective speech intelligibility scale. However it is possible to obtain 100% speech intelligibility with reverberation times of at least 0.4 - 0.5 s, and these reverberation times may be preferable in rooms with moderate ambient noise levels. For some metrics the reverberation time can be even higher, while still giving 100% speech intelligibility. The present study suggests an "ideal" and an "acceptable" maximum background-noise level for classrooms of 25 dB and 20 dB respectively below the voice level at 1 meter in front of the talker.

Speech intelligibility in rooms is determined by both room acoustics characteristics as well as speech-to-noiseratios. These two types of effects are combined in measures such as useful-to-detrimental sound ratios whichare directly related to speech intelligibility. This paper reports investigations of optimum acoustical conditionsfor classrooms using the ODEON room acoustics computer model. By determining conditions that relate tomaximum useful-to-detrimental sound ratios, optimum conditions for speech are determined. The results showthat an optimum mid-frequency reverberation time for a classroom is approximately 0.5 s, but speechintelligibility is not very sensitive to small deviations from this optimum. Speech intelligibility is influencedmore strongly by ambient noise levels. The optimum location of sound absorbing material was found to be onthe upper parts of the walls.

Aussi disponible en français: De nouvelles données permettront d'améliorer la performance acoustique des atriums

This work consists of comparisons of computer simulations of acoustical conditions in classrooms for a number of newer parameters and using two different computer models.

This document explains the important factors for insulating homes against aircraft noise. It is intended for residents living near airports, local authorities and others not expert in noise control procedures. The information relates to both improving the sound insulation of existing buildings as well as the basic issues for providing satisfactory sound insulation in new buildings.

Le présent document explique les aspects importants de l'insonorisation des maisons d'habitation contre les bruits d'aéronefs. Il s'adresse aux personnes vivant à proximité des aéroports, aux autorités locales et à tous ceux qui ne sont pas spécialistes des mesures antibruit. Il traite non seulement de l'amélioration de l'isolement acoustique d'immeubles existants, mais aussi des principes de base d'un isolement acoustiquesatisfaisant dans les bâtiments neufs.

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.