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Take a moment and listen, really listen, to your surroundings. What can you hear?
The murmur of conversation, a radio playing in someone’s cubicle, street traffic, perhaps a plane going by. We are often oblivious to the sounds around us. However, noise level can have a serious effect on us. The Acoustical Society of America (ASA), headquartered in Melville, NY, is devoted to serving the public and promoting a quality environment. Part of the College Park, MD-based American Institute of Physics, the ASA worked in association with the American National Standards Institute (ANSI), Washington, D.C., to create the first standard to control sound levels in classrooms.
The ASA was founded in 1929 and works in varied specialties, including acoustical oceanography, speech communications, and animal bioacoustics. Its mission is “to increase and diffuse the knowledge of acoustics and promote its practical applications.” The organization responds to internal and external requests to develop standards. Its accredited standards committee on noise has recently developed ANSI Standard S12.60-200X for acoustical levels in classrooms.
“Some individual members had felt there was a problem with acoustics in classrooms, and they came back time and time again to persuade us to look at this,” says David Lubman, co-chair, ANSI S12 Working Group, Westminster, CA. The committee sets up a working group – a task force, does research, and then drafts the standard. Once the organization came to understand there was a problem in classrooms, that group moved quickly to uncover what makes some schools so noisy.
The newly formed committee branched across members from existing committees, including the noise, architectural acoustics, and speech committees. The standards committee held a workshop to address the issue and delivered papers to the ASA to assess acoustics in schools. “After a few of those meetings and the equivalent of focus groups, we decided that the problem wasn’t a technological problem. It was a matter of implementing what was already known,” says Lubman. The committee recognized the need for a national standard in 1994.
According to Susan Blaeser, standard manager, ASA, Melville, NY, the ASA sent out a mass mailing to several groups involved in the education process, including schools; school boards; heads of education; the heating, ventilating, and air-conditioning community; and school construction companies. The response to this issue was disappointing. Adds Lubman, “It seemed like everyone didn’t recognize or perceive that it was a big problem.”
The ASA believes good acoustical qualities are essential in classrooms and all learning environments where speech communication is an important part of the learning process. “We discovered that in order to learn to read, you had to be able to hear the sounds. And only by hearing the sounds was it possible to reproduce the sounds,” says Lubman. In a poor acoustical environment, whether because it is too noisy or too reverberant, students can fall behind in their education because they cannot hear instructions. Moreover, students with any hearing problems would be at a great disadvantage in classrooms with poor acoustics.
Based on existing information, the ASA determined that for core classrooms the unoccupied noise level should not exceed 35 decibels, the level of conversation. “Our main concern was mainstream classrooms, not classrooms for special education,” says Blaeser. The ASA feels that excess background noise poses a barrier to learning, especially for students with minor hearing disabilities – the way some architectural features once presented a barrier to people in wheelchairs before the Americans with Disabilities Act.
A good acoustical environment is also less stressful and less tiring for teachers. According to the ASA, teachers lose on average two days a year because of voice fatigue. “Noise levels in classrooms have been going up slowly over the years; it has been so slow that many people do not know it,” says Lubman.
There are three major environmental conditions essential for learning: indoor air quality, lighting, and acoustics. Building codes and standards already exist in educational facilities with respect to adequate lighting, fresh air intake, humidity levels, and the presence of allergens. However, acoustics are underappreciated.
“Oddly enough, people do not always know when they can’t hear,” says Lubman. Students, according to the ASA, often blame themselves for not understanding their instructors, instead of realizing the space itself is a problem. Being able to hear well is especially crucial to learners who are unfamiliar with the material being taught and to non-English speakers. Adds Lubman, “But there is much more to speech communication than the lexical content of words; there is nuance. The informal parts of learning are as important as the formal parts of learning.”
“The standard speaks to new construction and major renovations, not going back to retrofit just on the basis of acoustics,” says Paul Schomer, standards director, Acoustical Society of America, Champaign, IL. The society recognizes the expense involved in upgrading deficient educational facilities and believes there are many ways to address acoustics in an economically practical manner.
Typically, acoustic consultants will evaluate three main elements in a school: noise level, reverberation time, and sound isolation. Common sources of acoustical problems are other classrooms, corridors, street traffic, and HVAC equipment. Building layout can contribute to noisy classrooms. “People will put in electrical boxes in two rooms back to back. Good practice is to isolate them so that you don’t create paths for sound to go through,” says Schomer.
“Thus the exclusion of noise and the reduction of reverberation are indispensable with adapting classrooms to the function of oral instructions,” from Acoustical Designing and Architecture (1950) by Verne Knudsen and Cyril Harris. The concept of quality acoustics has been around for a long time. The new standard is already stirring controversy. It has been strongly criticized by several organizations involved in school construction. The future of the standard is unclear, but what is clear is the sound quality of schools will be seen in a new light.
Regina Raiford (firstname.lastname@example.org) is senior editor at Buildings magazine.
Finally, if the standard is 35 decibels, then that appears to be a very low standard. I understand that 35 is the level of conversation. I am not aware of any scientific evidence that shows a health problem for decibel levels of less than 65 on an ongoing basis; in fact, the validated research appears to indicate that the health hazard level is a sustained 90-decibel level.
– David Warath, Executive Director,
Small School Districts Association,
We are extremely concerned with how this standard will impact our districts’ ability to provide adequate classroom space. We are certain that cost estimates for this standard provided by ASA (14.5-percent increase to building construction) are extremely low and that the impact of this kind of cost increase on school construction and renovation will be devastating to school districts throughout California and throughout the United States.
— Kevin R. Gordon, Executive Director,
California Association School Business Officials (CASBO),
Although noise reduction is an important issue, it should be considered within the larger context of all school construction issues. Only then should it be determined whether decibel levels are a higher priority for funding than alleviating overcrowded schools, housing pupils in adequate facilities, renovating dilapidated classrooms, completing seismic upgrades, complying with ADA requirements, creating safe play areas, providing class-sized reduction, and numerous other issues challenging the legislature in California.
— Thomas Duffy, Ed.D,
California’s Coalition for Adequate School Housing,
Our industry was not made aware of this standard, nor included in the development process. This is of particular concern because of the serious effect the standard will have on our industry and on schools. We would appreciate the opportunity to be heard on this issue. Approval of the standard will have a severe impact on our industry’s ability to supply modular classrooms to public and private school organizations across the nation.
— Judy Smith, Executive Director,
Modular Building Institute,