22 December 1999

If Kids Can't Hear So How Can They Learn?

by Kate Melville

Education is one of those touchy subjects where parents are apt to go ape over the smallest slight to their childrens intellectual ability. If you doubt this go and ask a friend why their kid is so dumb (we suggest upgrading your medical insurance first).

However the kid may not be dumb, it could be that their school just has terrible accoustics. At least this may be a contributory factor according to new research from Ohio State University.

In a study of 32 classrooms (in Ohio of course) the accoustics were so poor in most that they made learning and listening difficult for students. Of the 32 only two met the recommended standards (background noise levels of 30 decibels or less and a reverberation time of 0.4 seconds or less) set by the American Speech-Language-Hearing Association (ASHA). The researchers pointed to previous studies which showed that children's learning and speech capability is hindered when they can't hear well in the classroom.

"This is probably the most extensive acoustical study of classrooms ever. When sound bounces around it creates its own masking noise, and interferes with understanding speech", said Lawrence Feth, professor of speech and hearing science at Ohio State (sound bounces off of hard surfaces, and classrooms normally have hard floors).

The findings held across geographic, economic and social boundries; background noise and echoes were loud enough to interfere with the learning of children with even mild hearing problems, according to the accoustic levels recommended by the ASHA.

"One of the worst classrooms was in a school district that had some of the better classrooms," said Gail Whitelaw, adjunct associate professor of speech and hearing science. "So you can'tjust say the acoustics in a district are good or bad. It varies by the room. It's like real estate -- what matters is location, location, location."

The key seems to be that children are far more sensitive to bad acoustics because they are still learning language, while adults' larger vocabulary helps them compensate when they can't hear clearly.

"Even if kids have temporary hearing loss from an ear infection, and even if it's intermittent,it presents a big problem for understanding speech in a noisy environment. It only takes a small change in speech to noise ratio for a child to go from understanding almost everything to understanding very little," said Feth.

This problem is even worse with students who have hearing diifculties or where the language being taught is the students second language.

The study found that the biggest single source of background noise in classrooms is the heating and cooling system, because many schools have opted for individual units instead of quieter (but more expensive) central airconditioning. Carpet can also help reduce bacground noise , but can be a problem for children with allergies and or asthma.

Noise problems can be fixed with commercial noise control packages, but these are expensive (US$1000 per classroom). There are cheaper alternatives, curtains, wall hangings and sound-absorbing panels, but if these are not done properly they can increase rather than reduce the problems. So schools are stuck, few will be able to retrofit classrooms, but then again can they afford not to?

Feth plans to extend this research, and look at:

The relationship between room size and sound quality Whether the teachers who work in classrooms with poor sound quality experience more voice fatigue and take more sick days because they can't talk.

When his results become available we will do a follow-up story, but for now you might if your child seems to have a learning difficulty here is another issue that you will probably want to raise with your child's teacher.