Understanding Classroom Acoustic Solutions

This article describes the use of new impulse response measures and observations in existing Florida classrooms to document the classroom infrastructure on speech perception in the rooms. A series of 120 computer model studies in virtual classrooms using state-of-the-art technology are presented that define how specific architectural acoustic variables affect speech perception in classrooms. Recommendations are proposed for schools to meet the new American National Standards Institute (ANSI) 12.60 Standard on Classroom Acoustics based on the measurements and observations in existing classrooms and the computer model studies. Ten practical methods to design schools that can provide the high-quality acoustical environments required in the ANSI standard are summarized in this article. The primary research for these recommendations consisted of recording acoustical measurements of reverberation time and background noise, as well as newer acoustical measurements based on impulse response techniques, in 56 actual classrooms. Observations of classroom situations occurred in a subset of these schools. Computer and physical models of more than 120 classrooms were constructed and tested with varying room finish materials and background noise levels to study the combined effects of these architectural items on speech perception in the model rooms. The primary recommendations concern air conditioning system selection and noise control techniques to minimize interference with listening, interior classroom acoustic design principles for maximizing speech perception, documentation of teaching methods and classroom arrangements that result in improving speech intelligibility, and other factors that affect speech perception that are related to school design and planning.

KEYWORDS

Classroom acoustics - acoustical design - architectural acoustics - acoustical measurements - computer model - school design - speech intelligibility - speech perception

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