Assistive Technology

Listen Up!

Classroom sound amplification systems can make a difference in academic performance as well as the number of referrals to special education programs.

There are many possible interventions that can occur when a child performs poorly in school, but one that can be easily overlooked is a hearing check. Yet a growing body of research indicates hearing loss--even a minimal amount--can have a dramatic effect on everything from attention and behavior to academic performance. At the same time, data indicates, and experts in the field believe, that the introduction of sound reinforcement and sound amplification systems can help with this problem.

Normal hearing for children is 15 decibel hearing level (dB HL) or better at all frequencies with normal middle ear function. Anything less can place a child at risk in the academic setting.

There are approximately 46 million K-12 students in the United States; more than 9 million--about 20 percent of them--have some type and degree of hearing loss. Based on the number of audiologists employed by school districts to manage students with hearing loss, less than 1 percent of these children with hearing problems are receiving professional help through their schools.

Of course, it's possible that not nearly all those students need professional help with their hearing loss. In fact, many times the loss is not even noticeable by most observers, and the same loss likely would not affect the behavior of adults. However, for a child trying to integrate new information, even "minimal" hearing loss can have a huge impact on learning.

"The issue that needs to be addressed is hearing clearly for effective teaching and learning," says David H. Parish, president and CEO of Woodbury, MN-based Calypso Systems, a manufacturer of integrated classroom products, including classroom acoustic systems. He stresses that children who have trouble hearing what is going on in the classroom may perform below standards both academically and behaviorally.

"Studies show that children who fail basic hearing tests have to repeat a grade at 10 times the rate of those who pass them," says Parish. "That statistic clearly demonstrates that the ability to hear--especially at younger ages when language skills are not as advanced or for those learning English as a second language--is critical for good academic outcomes."

Loud and Clear
The Acoustical Society of America, in conjunction with the American National Standards Institute, has published standards that define, for classrooms, the acoustical standards necessary for effective teaching and learning environments. The key standard is signal-to-noise ratio. The "signal" is the teacher's voice or the audio of media employed in instruction. "Noise" is everything else that makes it more difficult to hear the signal: students' chatter, the fish tank, street noise, HVAC systems, and so on. "The signal needs to be sufficiently greater than noise to be heard and understood, and very often that is not the case," says Parish.

Another eye-opening statistic in this context: Roughly 72 percent of all children referred to special education courses also fail a basic hearing test. "Why does this happen?" asks Parish. "Which is the cause and which is the effect here?"

 According to Parish, these children are more easily distracted, which makes it more likely that they will be disruptive in the classroom. As a result, they often move into special education programs. This raises the question: Could schools reduce the number of referrals into special education through the introduction of sound reinforcement and sound amplification systems?  Studies suggest the answer may be "yes."

According to research compiled by Pamela Millett, assistant professor and educational audiologist at York University in Toronto, a number of studies show decreases in special education referral rates following installation of sound field acoustic systems across school districts.

For example, in the Oconto Falls School District (WI), special education referral rates fell from an average of 7.72 percent between 1989 and 1998 to 4.6 percent between 1998 and 2000, when sound field amplification systems were installed in all classrooms in the district from kindergarten to grade 5. This is a reduction of more than 40 percent.

Long-term data from the Mainstream Amplification Resource Room Study (MARRS) project, funded by the US Department of Education under the Elementary and Secondary Education Act, supports this finding. The project's data indicates that special education referral rates throughout the nation fell at the same rate as in Oconto Falls--almost 40 percent--after five years of sound field use in classrooms across school districts participating in the study.

Both studies analyzed the results of systems designed to create a uniform sound field in which the teacher's voice (i.e., the desired audio signal) is heard equally well regardless of where a student sits in the room.

Ending the Echo Effect
Most school classrooms are simple square cinder block arrangements with hard surfaces, like blackboards and windows, spanning the walls. In such an environment, sound can bounce around like a pingpong ball, a perfect breeding ground for excessive reverberations that can cause plenty of "ear fatigue" among students and equivalent vocal strain for teachers.

Sound amplification systems do not necessarily correct for this echo effect, but simple acoustic panels do. Companies like SoundproofCow, Acoustics First, and Primacoustic make these fabric-covered sound-absorbing panels for many industries; for the K-12 market their panel solutions are targeted to the sound challenges inherent in classrooms, gymnasiums, and libraries, usually at a cost that most schools can afford.

Primacoustic, for instance, has created tables to help educators calculate how many panels any given room will need to help reduce sound reverberations. If a classroom floor size is 400 square feet, for example, and the ceiling is 9 feet, you will need anywhere from 72 to 180 square feet of acoustic panels, depending on whether you want minimal, light, medium, or "extra" coverage. The company says that most schools "find that a 'light' level of treatment provides sufficient sound abatement while keeping the budget in check." If budgets are tight, Primacoustic suggests that schools start with a minimal treatment and then work up from there as funds become available. By simply placing panels so that each parallel surface has some treatment, schools can dramatically reduce the echo effect in their classrooms. 

Speak Into the Mic
The components usually involved in a unified sound field system are speakers installed in the ceiling and a wireless microphone on the teacher. The microphone transmits its signal to some type of receiver, typically mounted on the ceiling or a wall. The wireless signal reflects and bounces around the room, reflecting off the walls and ensuring a very high percentage of room coverage. The teacher can move anywhere in the room and have the signal remain effective. The wireless receiver converts the signal from the teacher's microphone to an audio signal and sends it to an amplifier, which then sends it to the speakers. Often, the wireless receiver and amplifier are in the same box, although that doesn't have to be the case.

According to the MARRS study, unified sound field amplification "enhances the clarity of oral instructions, promotes student attention, lessens teacher voice fatigue, and increases academic achievement scores, particularly for students with mild hearing loss."

Sound Financials
While improved behavior and academic performance seem like good reasons to adopt classroom acoustic systems, so too is return on investment. "Our district realized it was spending more money than necessary to send hearing-impaired students to other districts because we didn't have the facilities to serve them," says Matt Cirigliano, IT manager at Delaware Valley Regional High School (NJ). "With the acoustic system we put in, we'll be able to recoup the cost of installation in under a year, just from savings on out-of-district kids."

The Delaware Valley school hired an education specialist for the hearing impaired to train teachers in using the system to get the most out of it for those with hearing challenges. Cirigliano recalls, "The consultant came with materials to help everyone understand how hearing-impaired students hear, and to make adjustments in the acoustics accordingly."

Parish says the financial impact of amplification systems could be huge. "As a national average, special education costs twice as much as general education. On average, school districts spend roughly 25 percent of their overall operating budget on special education when only 12 percent or so of the kids are in those classes. These numbers spell out the financial potential of these systems."

Sound Performance
Barbara Martin, principal of Monarch School in the Gwinnett County Public Schools (GA), says performance was at the heart of her school's decision to implement an amplification system. "I don't have statistics on students who are underperforming due to hearing loss, but what made us go ahead with the system was a feeling that kids in the corners or at the back of the room weren't being served, and teachers were constantly having to raise their voices," she says. "We wanted something that would amplify the sound throughout the room, ensure that the teacher's instruction was heard throughout the day, and make every second of teaching time available to the students."

Cheryl Myers, a preschool teacher for the deaf and hard of hearing at Monarch School, says the system has made a noticeable difference. "We see a clear difference in how the children attend to the teacher's voice," she says. "Now that they hear the teacher, regardless of where they are in the classroom, their attention is better, their behavior is better, and comprehension has increased."

According to Martin, teachers are not repeating directions as frequently as they had to before, so there's definitely more time on task. "The teacher gives a direction once, and no matter where the student is, the direction is taken," she says. "Before it was, 'Time to clean up. Time to clean up. Boys and girls, it's time to clean up.' Now they say it once and the students hear it."

Classroom Sound System Vendors: A Quick Reference Guide
That classroom audio systems are an increasingly important part of the audiovisual market segment can be seen in the growing number of national and international suppliers of the equipment. While the sheer number of manufacturers and distributors would be prohibitive to publish, the list below contains some of the significant corporate enterprises serving the audio needs of educational facilities in North America.
Bogen Paging
Califone International
Calypso Systems
Cetacea Sound
Lightspeed Technologies
Smart Technologies