Free Booklets Available On Classroom Acoustics
According to classroom acoustics, a publication of the technical committee on architectural acoustics of the Acoustical Society of America (ASA), speech intelligibility among listeners with normal hearing is about 75 percent or less in many of today’s classrooms. This means that listeners miss one out of four words read to them off a list. Adults and older children can use their experience to “fill in the gaps” and make sense of what’s being said. Younger children who are just exploring language, ESL students, the learning disabled, and the hard of hearing do not have that luxury.
That number of hard-of-hearing students is remarkably large and flexible. The Centers for Disease Control and Prevention estimates that up to 15 percent of school-age children suffer from temporary hearing loss at any time. Allergies, ear infections, and colds or other forms of congestion mean that today’s competent hearer could be tomorrow’s hard-of-hearing student.
The good news is that making classrooms acoustically sound is neither difficult nor expensive. A bit of forethought, a small upgrade in materials, and acoustical enhancement is all it takes to make classrooms and other core learning spaces better. “The best way to solve acoustics problems is to prevent them beforehand, not correct them after the fact,” continues the publication. “Renovation of poorly designed classrooms is much more expensive.”
Thankfully, more and more states are implementing ANSI/ASA S12.60-2002, Acoustical Performance Criteria, Design Requirements and Guidelines for Schools. Consistent with long-standing recommendations for good practice in educational settings, the new standard sets maximum limits for background noise (35 decibels) and reverberation time (0.6 to 0.7 seconds) for unoccupied classrooms.
To help architects, planners create learning spaces that meet the guidelines, the ASA has published three booklets on Classroom Acoustics topics that can be downloaded for free on their website, www.acousticalsociety.org/classroom-acoustics.