From the day they enter Kindergarden, children spend long stretches of time learning. Children develop their intellectual, social, and communication skills through their exposure to a variety of situations and experiences, and the classroom is central to the learning process for at least 12 years. The classroom experience is supposed to offer kids the stimuli and tools necessary to focus within a controlled environment, and eventually send them out into the world prepared to work, perhaps raise families, travel - whatever they choose to do with their proverbial oyster.
Now, consider the importance of the classroom environment to a child’s learning process. Researchers are finding that background noise and reverberation – much of which may not even be noticed by adults – adversely affects the learning environment of the classroom, particularly for younger children. Poor classroom acoustics add an extra burden to children with learning disabilities, speech impediments, and impaired hearing, even if the hearing impairment is temporary.
The harmful effect of noise on young children has been well documented. Apart from physiological hearing damage from prolonged exposure, a noisy environment can dull a child's listening skills. Just as frightening, children exposed to noisy surroundings routinely can lose the ability to distinguish some of the subtle speech components essential to the mastery of language. In today’s noisy world, many children have come to accept noise as a natural element in their everyday activities at home, in school or daycare, and in public places. The classroom should provide an environmental model that facilitates communication for all children regardless of their backgrounds or handicaps, and that requires acoustically optimized sourroundings.
Two important characteristics of an acoustically optimized classroom are a low background noise level and a low reverberation time. Classroom background noise may be caused by a heating/cooling ventilation (HVAC) unit, activity in an adjacent classroom or hallway, highway traffic or aircraft noise bleeding in from outside, student activity within the classroom, or any combination of these. Reverberation is the multiple reflections of sounds ricocheting off of hard surfaces within a room that can prolong and distort the original sound and interfere with speech intelligibility. It has the added effect of amplifying background noises, which compounds the problem.
A classroom with reverberant noise issues must be treated with sound absorbing material placed on top of the reflecting surfaces. Sound absorption also helps to reduce background noise levels and, by improving speech intelligibility, reduces the need for teachers to speak in raised voices in order to be heard by all pupils.
In Canada and Europe, workable classroom noise abatement policies have been in place for years, and the use of noise abatement materials is being implemented indoors, in addition to outdoor noise barrier fencing and structures to protect the hearing of both children and teachers.
Many older concrete structured schools are the worst classroom noise offenders, and a variety of corrective noise absorbing and noise barrier solutions are available that work easily with many of these old structures. Corrective action may also require the installation of reverberant noise absorping materials to the walls and ceilings too.
Obviously, a supportive acoustic environment is critical in any listening space, particularly the classroom where so much is at stake. Ideally, the acoustic quality of a classroom will enhance and project the teacher's voice, have a subdued level of reverberation or echo, and prevent the intrusion of unwanted sound, whether from the traffic outdoors, trains, airplanes, the building’s mechanical and HVAC systems and noise in adjacent spaces.
When you consider that approximately 60 percent of all classroom learning activities involve students listening to and participating in spoken communications with the teacher and other students, the presence of any serious, continuous noise should be a priority for corrective measures to be taken. Yet noise remains far too prevalent in American schools.
According to the United States General Accounting Office, millions of students attend schools with unsatisfactory acoustical conditions. 21,900 schools exhibit poor acoustics or noise control, affecting more than 11 million students. Twenty-eight percent of all U.S. schools report unsatisfactory or very unsatisfactory environmental noise conditions -- higher than ventilation (27 percent), physical security (24 percent), indoor air quality (19 percent), heating (18 percent), or lighting (16 percent).
The excessive noise levels and lack of support for speech in these classrooms have failed countless students and led to difficulties in learning and instruction. The impediment these classrooms pose to learning is often under-appreciated by students, teachers, and administrators. In some cases, problems caused by poor acoustic conditions may have been falsely attributed to other factors (teacher performance, socio-economic factors, etc). The poor listening conditions in American classrooms results from a lack of understanding and awareness of the detrimental impact that noise and reverberation have on student learning.