Classroom Amplification

Students can't hear? No problem. Just turn up the volume, right? Not quite. One of the latest and fastest growing trends in high-tech is classroom amplification. But just buying a sound amplification system and installing it does not necessarily make an improvement in students’ hearing. It may make it worse. On the other hand, if it's done right, and more and more manufacturers are doing it right, the improvements can be dramatic.

But, since the overall trend appears to be much more positive than negative, let's start with the latter: some pitfalls to avoid.

The Acoustical Society of America, Melville, N.Y., recently published a paper on its "Position on the Use of Sound Amplification in the Classroom." The following, with slight editing, is drawn from that paper.

In recognizing the importance of good speech communication to classroom learning, the American National Standards Institute (ANSI) Accredited Standards Committee S12, Noise, which is administered by the society, developed a standard for classroom acoustics — ANSI S12.60.2002. The standard specifies the acoustical conditions needed to achieve acceptable speech intelligibility for teachers and students in mainstream classrooms. The standard specifies maximum sound levels for classrooms, maximum reverberation times and minimum sound insulation requirements between classrooms and adjacent spaces.

There are three channels for speech communication for classrooms: (1) student-to-student, (2) student-to-teacher and (3) teacher-to-student. Sound amplification only improves the third channel, if at all. If the room is too reverberant, then sound amplification does nothing to improve communication; it only increases the sound level. Sound amplification does little to improve and may worsen the first two channels of communication, student-to-student and student-to-teacher. Sound amplification refers to any method that acoustically amplifies sound.

The society maintains there are two additional reasons why sound amplification should not be routinely employed in classrooms.

The first is that sound amplification increases rather than reduces overall classroom sound levels. Such increased sound levels may be excessive for comfortable listening. Also, unless classroom walls, ceilings and floors are acoustically upgraded to improve their sound insulation, amplified sound may be heard in adjacent classrooms, interfering with learning there.

Second, sound amplification systems require regular maintenance and user training. Improperly maintained microphones and loudspeakers or poor user skills can cause even poorer speech communication than no amplification system. Good classroom acoustics can be achieved passively with good architectural design practice. Good classroom acoustics in existing schools can usually be achieved through renovation. Unlike amplification, good acoustics that are "built in" to the classroom require little or no maintenance or user training.

The upside to this downside is that there is the clear ANSI standard that can be checked to see if any system you are considering purchasing meets the criteria.

And even bigger upside is that as more and more manufacturers enter this arena, the systems are improving to meet the deficits pointed out above.

Somebody must be doing something right, for there are numerous studies showing most impressive benefits of an audio-enhanced learning environment. One of the most noted is the widely respected independent research study conducted in 2003 at Trost Elementary School in Canby, Ore. The researchers compared data collected before and after the installation of sound field systems, both statewide and within their school. Here is the summary of the Trost School findings.

  • 35 percent higher first grade scores on the Dynamic Indicators of Basic Early Literary Skills (DIBELS).
  • 21 percent higher scores on the Technology Enhanced Student Assessment (standardized state test).
  • 21 percent higher scores on the Developmental Reading Assessment (DRA).
  • 35 percent higher words-per-minute reading scores by 4th and 5th graders.
  • 72 percent decrease in teacher redirections.
  • 43 percent decrease in off-task student behaviors.

There are basically two sets on components to these enhanced sound systems. The first is the sound system in itself, which has, with some variations, been around for some time. Included are receiver, switcher/amplifier, cables and usually at least four strategically located ceiling mounted speakers. The new addition, which is fueling the new popularity, is the wireless microphone the teacher wears. Not that microphones in themselves are particularly new, but the improvements manufacturers are bringing to them are.

Heather Johnston, product manager, Epson American, Inc., Long Beach, Calif., says she's "gone out to visit a number of different schools to see how their classrooms were set up. I found that many projectors and other visual aids were not being used. Teachers were asking for larger speakers and many were buying some kind of microphone to their computer-connected speakers out of their own pockets. They asked if we might be willing to make a good microphone."

Epson accepted the challenge and developed the product about two-and-a-half years ago.

This one is amplified through four large speakers, but itself is very small, worn as a pendant around the neck. You can also buy a handheld one to hand to a student or a guest speaker. It can coordinate to other audio devices, as well as DVD players and computer programs. With a remote, you can fade features in and out, adjust the volume and set it for what is optimal for that room. Johnston says many similar microphones are coming to market. "Teachers have found they can speak naturally, without losing their voice, and it's much more pleasant for the students," Johnton says. "Before, students in the front row often felt they were being yelled at while those in back could barely hear."

Anthony Cortes, director, sales and marketing for Extron Electronics, in Anaheim, Calif., says his company also saw this trend about four years ago and brought their microphone to market about two years ago. This one also comes a few hundred dollars cheaper than the standard stand alone microphone, but also if purchased in conjunction with the overall sound system.

A driving force behind acceptance of this technology, according to Cortes, is the labor unions that are getting the microphones mandated in many states to protect against teachers' laryngitis. Cortes also says that the newer microphones are also designed to remove ambient or background reverberation instead of just making them louder, as do the personal communication systems designed for hearing impaired students. Also, these microphones operate on either radio frequency (RF) or infra-red (IR). Cortes recommends the latter, for RF tends to go through walls, but IR won't.

An option that Extron has added is that a teacher can easily send an e-mail that will trigger an alarm to bring assistance to the classroom. Cortes adds, "We've found teachers are willing to forgo some of the other technology in order to have this."

Randy Ryan, director of technology for Bel Valle Independent Schools District, in Bel Valle, Texas, says his district chose to go with this type of amplification system. "We heard about one big installation in California where the teachers were ecstatic. This technology was pretty new to our teachers, but once they became familiar with it they were very responsive,” Ryan explains. “It creates a new excitement in the classroom."

The complete system is going into all of the core classrooms of the 11 schools in the district, and will be a part of the new elementary and middle schools being built. The cost for the entire sound amplification package ranges from $2,500 to $4,500 per room. "Looked at from the outside, this may seem expensive, but the project management system allows us to manage all our projectors, etc., all from a single location." Ryan adds that the price is comparable to what it would cost to have separate voice enhancements for all of the multiple audio/visual devices from laptops to CDs to iPods — all of which are integrated into the district's one system.

Claire Robinson, technology and implementation manager for the Seminole County Public Schools in Florida, reports that the Midway Elementary School of the Arts, in Sanford, recently debuted its new 110,000-square-foot, state-of-the-art facility, complete with a projector system and voice amplification system in every classroom for both teachers and students.

The first LEED-certified school in the district, Midway accommodates 817 students, almost double its previous location. With the spacious two-story building featuring suites for ballet, art (2-D and 3-D exploration), orchestra, band and musical theater, as well as a digital arts computer lab, full performance stage, outdoor amphitheater, a TV production studio and more, the need for clear sound in many different environments is obvious.

Robinson says they tested out three different brands on the teachers and students. "We found there was not that much difference from one to the other, often a matter of preference, such as the design of the microphone. We ended up using all three brands and feel comfortable with all of them."

To leave the final word with a teacher, Catherine Zeuli, who was named Teacher of the Year for Seminole County Public Schools. Zeuli says of her first grade class, "We moved from a school that didn't have this system to this one that does. The kids love it. They don't have to struggle to hear me. And since they're able to hear me better, they are actively listening and their behavior is better. It's been a positive experience for all of us."