Sound standard for schools is key to learning.

Administrators are being held legally accountable for student skills that are impacted by poor speech intelligibility in loud, reverberant classroom environments. Those skills include phonics, reading, attention skills, listening skills, math and social skills and behaviors.

Acoustics impact the achievement of all students, especially those with learning disabilities, English language learners, those with hearing loss and those who are visually impaired or from low income families. A California study (Lucas, 1981) found that reading scores began to decline as classroom noise levels exceeded 35dB, and the effects were cumulative over the years.

The brain is designed to function auditorily, and the medical community is concerned. Why does the school environ merit offer so much noise?

Listen to learn

According to the World Health Organization, the critical effects of noise for schools are on "speech interference, disturbance of information extraction (comprehension and reading acquisition), message communication and annoyance. To be able to hear and understand spoken messages in classrooms, the background sound pressure level should not exceed 35 dB LAeq during teaching sessions. For hearing impaired children, an even lower sound pressure level may be needed.

"The reverberation time in the classroom should be about 0.6 s, and preferably lower for hearing-impaired children. For assembly halls and cafeterias in school buildings, the reverberation time should be less than 1s" (World Health Organization, guideline 4.3.2).

Too many learning environments are too noisy and reverberant for children and teachers to understand each other. The noise of HVAC systems is a one common problem. Another common problem is excessive reverberation, a consequence of hard sound reflecting off interior surfaces. Reverberation can be tamed by treating room surfaces (ceilings, walls and floors) with sound-absorbing materials.

The American National Standards Institute published a new standard for sound levels in schools in 2002, after many years of asking for public and professional input. The 56-member working group that helped develop the standards includes educators, architects, engineers, professionals in speech and hearing, and members of the Air Conditioning and Refrigeration Institute.

Children more vulnerable

On any given day, more than 45 percent of early elementary school students may have hearing loss from ear infections, respiratory infections or colds, or undetected permanent hearing loss.

Data from animal experiments indicate that children may be more vulnerable in acquiring noise-induced hearing impairment than adults. The risk for noise-induced hearing impairment increases when noise exposure is combined with vibrations, ototoxic drugs or chemicals (Fechter, 1999, in WHO guidelines). Most lunchrooms are more than 70dBA.

Don't panic. Many classrooms with central air are close to the standard. Purchase a sound level meter (available at Radio Shack) and spend some time reading about acoustics. Complying with the standards does not have to be expensive, and it is voluntary. The cost of not addressing the sound environment is higher than cost of ignoring problems that result in special education referrals and attention and listening deficits, which will certainly impact learning and long-term costs.

For more information, go to www.parentsvoice.org, www.who.org or www.edfacilities.org.

References

Lucas, Jerome. (1981). Effects of Noise on Academic Achievement and Classroom Behavior. California Health and Welfare Agency, Department of Health Services.

Carolyn Knox is a teacher, author, mother of a child with fluctuating hearing loss and a member of Parents Voice.