Classroom Acoustics

Revised for 2000 CE

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Home Page of Classroom Acoustics

This web site is a resource for those concerned with meeting new standards for the acoustics of classrooms. It will be updated frequently with current events and information of interest to parents, educators, school planners, architects, school boards and others. Watch this space....!

Mike Nixon 1937 - 2007

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Mike Nixon

Essay

What's Wrong with our Classrooms?

Childhood is a time of intensive, continuous learning. Both inside and outside the classroom, children practice and develop their social, intellectual and communication skills in a variety of situations. The classroom experience is an opportunity to focus on these critical skills in a controlled environment and provide the stimuli needed to help a child realize his or her full potential.

One of the corner stones of a child's early education is the development of language skills. An instinctive grasp of phonetic structure and grammatical rules comes about only through repeated exposure to clear, unambiguous auditory interaction with parents, teachers and peers. Too often such interaction is corrupted or inhibited by the acoustical environment in which it takes place.

The harmful effect of noise on young children has been well documented (Maxwell and Evans). Apart from physiological hearing damage from prolonged exposure, a noisy environment can dull a child's listening skills. Children can lose the ability to distinguish some of the subtle speech components (see below) essential to the mastery of language. Too many children accept noise as the natural background to their activities at home, in daycare or in public places. The classroom should provide a model for an environment that facilitates communication for all children regardless of their backgrounds or handicaps.

Two important characteristics of an acoustically optimized classroom are a low background noise level and a low reverberation time. The background noise may be from a heating/ventilation unit, activity in an adjacent classroom or corridor, traffic or aircraft noise, student activity within the classroom, or any combination of these. Reverberation is the multiple reflections of sounds within a room that can prolong and distort the original sound components. Speech intelligibility is compromised when a soft vocal element is masked by the reflected sound of a preceding louder element. Reverberation also has the effect of amplifying background noises.

Communication over a high background noise can be assisted with a voice amplification (sound field) system. A reverberant room, however, cannot be improved electronically and a "live" room must be treated with sound absorbing materials over the reflecting surfaces. Sound absorption also helps to reduce background noise levels and, by improving speech intelligibility, reduces the need for raised voices.

Many older schools built with high, concrete ceilings and equipped with individual room heating/ventilation units will not meet the recommended standards without modification. The first step should be an acoustical survey to measure background levels, noise isolation and the reverberation characteristics of the room. Corrective action may require the installation of a suspended acoustical tile ceiling (with new light fixtures). Seals on doors and windows can reduce noise from outside. Noisy individual heating units will need to be serviced, upgraded or replaced with a forced air central heating system.

The Importance of Phonemic Awareness

Excerpted from Phonemic Awareness in Young Children, (Marilyn Jager Adams et al) http://www.brookespublishing.com/store/books/adams-3211/excerpt.htm

"Before children can make any sense of the alphabetic principle, they must understand that those sounds that are paired with the letters are one and the same as the sounds of speech. For those of us who already know how to read and write, this realization seems very basic, almost transparent. Nevertheless, research shows that the very notion that spoken language is made up of sequences of these little sounds does not come naturally or easily to human beings.

The small units of speech that correspond to letters of an alphabetic writing system are called phonemes. Thus, the awareness that language is composed of these small sounds is termed phonemic awareness. Research indicates that, without direct instructional support, phonemic awareness eludes roughly 25% of middle-class first graders and substantially more of those who come from less literacy-rich backgrounds. Furthermore, these children evidence serious difficulty in learning to read and write (see Adams, 1990, for a review).

Why is awareness of phonemes so difficult? The problem, in large measure, is that people do not attend to the sounds of phonemes as they produce or listen to speech. Instead, they process the phonemes automatically, directing their active attention to the meaning and force of the utterance as a whole. The challenge, therefore, is to find ways to get children to notice the phonemes, to discover their existence and separability. Fortunately, many of the activities involving rhyme, rhythm, listening, and sounds that have long been enjoyed with preschool-age children are ideally suited for this purpose. In fact, with this goal in mind, all such activities can be used effectively toward helping children to develop phonemic awareness."

Phonological Awareness

Frances Gilbert, the children’s book author and educator has been quoted as saying "Rhythm binds language, language binds emotion and emotion binds meaning." To strengthen phonological awareness, she says, children need to “play” with words – to prolong blends and to tease out the long rhythms of multi-syllable words. “They need to feel words in their mouths in order to stir up the language that is within them…”

How Did We Get Here?

Studies of the effects of noise on children go back many years. The present heightened awareness is reflected in a 1997 article in "Sound and Vibration" by Towne and Anderson titled "The Changing Sound of Education". Earlier, in 1996 a sub-committee of the Acoustical Society of America had requested the Access Board to include acoustical standards in new rules on children's facilities. The Access Board finally took notice when a mother of a hearing-impaired child in Georgia submitted a petition related to the subject. The board sent a representative to the next meeting of the ASA in State College Pennsylvania in June 1997. Some excellent papers presented at that meeting focussed on the classroom environment. A well attended workshop held after the conference highlighted the issue of accessibility, not just for students with hearing loss, but for all children as a special class. The ball was rolling.....

We asked Mike Nixon, a long time advocate for improved architectural acoustics, to fill in the blanks in the above summary. He responded with his personal notes on the activities that led up to the present widening interest in Classroom Acoustics.