Sound Systems For Hearing Impaired Help All Students, Says UF Expert

September 19, 1996

GAINESVILLE — Using special sound systems in classrooms helps kids hear better and leads to increased test scores and fewer behavioral problems, says a University of Florida professor.

According to UF professor of audiology Carl Crandell, when teachers use sound field FM systems — technology originally designed for the hearing-impaired — students with normal hearing hear better and improve scholastically.

“Our research shows dramatic improvements in students’ performance including reading and spelling skills and overall test scores when sound field systems are used in regular classrooms,” he said. “In fact, every study done on the effects of this technology has shown equally significant results. Academics improve, perception improves and behavior problems decline.”

The reason for the drastic improvements is that the system compensates for the noise and reverberation typically found in classrooms, said Crandell, co-author of Sound-Field FM Amplification: Theory and Practical Applications. When children don’t hear well, their behavior is affected, they lose attention easily and consequently, their academic performance suffers.

“Our research shows that many children with normal hearing perform near the same level as children with hearing loss when exposed to background noise,” he said. “The noise levels of the classrooms they’re being taught in are not appropriate for their perception and, thus, their learning.”

In one study, Crandell looked at children ages 5 to 7 and found they hear about 89 percent of the information presented to them while seated in the front of the room. Seated in the middle of the room — about 12 feet away from the speaker — their perception drops to 55 percent. In the back of the room, they hear about 36 percent of what’s being said.

“With the sound field FM systems, we’ve found that wherever a child is sitting in the classroom, his/her perception never drops below approximately 85 percent,” he said.

The technology consists of a wireless microphone worn near the teacher’s mouth which allows his/her voice to be amplified through one or more loudspeakers placed throughout the classroom.

A number of teachers across the country already use the device, including Shirley Davis, who used the system for two years while she taught second grade at a private Christian school, the Rock School of Gainesville. She noticed a dramatic improvement when she administered an annual standardized test, one year without the device and one year with it.

“When I used the system, the students finished 45 minutes earlier than they did the previous year when I didn’t use it,” she said. “Everything was the same except that I didn’t have to continually repeat myself, so the students heard and understood the directions the first time. It saved them time since they didn’t have to keep asking me to explain things over and over.”

Davis also noticed that children who were otherwise slow to respond to directions or who always asked to have things repeated seemed to perform better.

The device costs between $700 and $800 and has an average lifespan of 10 years. Unfortunately, said Crandell, in an effort to save money many people try to build their own units expecting to get the same results.

“It does more than amplify the teacher’s voice. It creates a diffuse’ field where everybody can hear everything well,” he said. “A lot of times a homemade system will do more harm than good. If it doesn’t sound good, people aren’t going to listen and that defeats the whole purpose.”