The Importance of Good Classroom AcousticsEAA Infographic  Infographic Text ContentWhy Classroom Acoustics MatterAs we build new schools and renovate old ones, there are numerous factors that must be considered in order to optimize learning outcomes for all students. Children learn in the classroom primarily through hearing the spoken language of their teachers and peers — and they can hear clearly only if the room has good acoustics. Classroom acoustics involve background noise and reverberation (the reflection of sounds within a room). Reductions in classroom noise and reverberation significantly benefit students, especially those with hearing and listening problems. Required limits on noise and reverberation that support classroom learning are provided in standards such as ANSI/ASA S12.60. Common Causes of Classroom NoiseHVAC units, electronic equipment, external classroom noise, outside noise, lighting, classroom pets, plumbing, and noise generated by students. Note: When choosing a new HVAC unit or treating an existing unit, it's important to consider how HVAC noise contributes to poor classroom acoustics. Common Causes of ReverberationSounds reflecting off primarily large, flat, hard surfaces such as sheet-rocked walls and ceilings. ANSI/ASA S12.60-2010 StandardsThese are the accepted standards for classroom acoustics required by the American National Standards Institute and the Acoustical Society of America.
*Classrooms should be built to be adaptable to a 0.3 second reverberation time for children with hearing problems or other special listening needs. Properties of Classroom AcousticsNoise — Any sound that interferes with what an individual wants or needs to hear. Background noise should be kept as low as possible. Signal-to-Noise Ratio — The relationship of the intensity of a desired sound (e.g., speech, music) to background noise. Noise should be reduced so that the desired sound is louder by at least 15 dB. This is referred to as a +15 dB speech-to-noise ratio. Reverberation — The repeated reflection of sounds off hard, flat surfaces in a room. How long sound reflections take to subside is called the reverberation time. Since these reflections can muddle the original sound, classrooms should be designed so reflections subside quickly. Reducing reverberation time is accomplished by placing sound-absorbing materials in the room, primarily on large areas such as ceilings and walls. Critical Distance — Speech from a talker at a close distance creates direct sound energy. As distance from the talker increases, the speech contains more reflections from room surfaces. Critical distance is the point where direct and reflected sound energy are heard equally. Within this critical distance a student should hear the talker most clearly — which is especially important for students with hearing and listening problems. Who Is Most Susceptible?Poor classroom acoustics affect all students, but the following groups are at higher risk for learning difficulties as a result of excessive noise: students with any permanent or fluctuating hearing loss (ear infections are particularly common in young children), younger students, children with auditory processing disorders, children with learning disabilities and developmental delays, children with articulation and language disorders, children with attention deficits, and second language learners. Who to ContactYour school district's educational audiologist is an excellent resource when seeking more information on classroom acoustics. These professionals can comment specifically on the acoustical conditions in your schools. You may also contact your state's chapter of the American Academy of Audiology, the American Speech-Language-Hearing Association, or the Educational Audiology Association at www.edaud.org. References
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