AWC17 Keynote: National Classroom Acoustics Std.

bradley portrait


John S. Bradley, Ph.D., recently retired from the position of Principal Research Officer at the National Research council after 40 years of working in acoustics research, mostly at NRC. His research included work on: sound insulation against outdoor aircraft noise, work on open plan office assessment and design, studies of speech intelligibility in rooms, and the rating of the speech privacy provided by rooms along with efforts to make the understanding and evaluation of performance spaces a more quantitative process. Where possible his work has included subjective evaluations of sounds as well as efforts to obtain better physical measurements. He was awarded the Sabine Silver Medal in Architectural Acoustics from Acoustical Society of America in December 2008, and the Rayleigh Medal for outstanding contributions to acoustics from the Institute of Acoustics (UK), presented in May 2011. He is a Fellow of the Acoustical Society of America and has been a member of working groups of: ISO, CSA, CGSB, ANSI, WHO, and the American Academy of Sciences. He has served as the Editor of Canadian Acoustics (3 years), the CAA Secretary, (1 year) and the President of CAA (5 years). 

A Rationale for a National Classroom Acoustics Standard

Although most measurement studies in classrooms have indicated ambient noise levels are too high for high quality speech communication, there are no national standards or requirements for classroom acoustics in Canada. Speech communication between a teacher and students and between students are probably the most noise sensitive activities in classrooms and are critical for maximizing the success of learning activities in classrooms. Extensive Canadian research by several Canadian researchers has identified the acoustical needs of elementary school classrooms and also has developed an understanding of the acoustical needs for university classrooms. Acoustical requirements can usually be explained in terms of obtaining adequate speech-to-noise ratios, where `speech` is the sound we want to hear and noise is other unwanted sounds including ambient noise and also some room reflections of the speech sounds. This lecture will discuss our understanding of the required acoustical conditions for classrooms based on the results of previous classroom studies and describe the particular acoustical needs of younger children. These previous results can be used to set acoustical requirements for various types of classrooms including those for younger students and others with particular special needs. 

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