Acoustic Design in Classrooms – What You Need to Know
Mark Holden | March 30, 2017
An abundance of scientific evidence supports the notion that better acoustic design in classrooms improves learning. But many design and construction decisions can work against students and teachers. Building a school on a noisy site, for instance, can inhibit learning.
Unfortunately, there is no standardized procedure for school site selection. The process is under the jurisdiction of school boards, municipalities, and the states. Often, planning agencies also weigh in. Today, accessibility dominates the site selection process. For instance, here’s what the American Planning Association recommends: “City and school officials must agree on policy relating to walking distance, travel time, and use of private and public means of vehicular transportation.” With little government recognition of the issue, acoustics often receive scant attention.
Of course, schools that are situated close to transportation to satisfy accessibility regulations are also subject to noise from cars, buses, trucks, trains, and airplanes that can be heard inside classrooms. While it would be ideal to situate every school away from these distractions, such a requirement would be impractical in cities and other densely populated environments.
Schools in noisy locations sometimes call in acoustic design experts to correct existing problems. Remediation is not impossible, but many of these problems could have been addressed far less expensively in the initial design process. Adjusting how a building sits on a site, window placement, wall design, and landscape grading can address many acoustic issues before construction begins.
Another major challenge facing acoustic design firms is tied to the heating, ventilation, and air conditioning systems (HVAC). Before designers became aware of acoustic design, it was common to place ductless HVAC systems under classroom windows. The low cost and flexibility of these systems trumped any concerns about noise.
Scientific studies connecting better acoustics to better learning led industry and education to develop standards for acceptable levels of background noise. While adopting acoustic standards is voluntary across the country, many school districts have made them mandatory.
The standards establish a strict maximum background noise level. At the time this criterion was established, most of the school HVAC systems failed to meet the new requirements.
As schools modernized, the HVAC industry at first had no answer. They claimed that there was no generally accepted way to measure the noise levels of HVAC units. During the early 2000s, however, the American Refrigeration Institute (ARI) developed the ARI Standard 260 – Sound Rating of Ducted Air-Moving and Conditioning Equipment. This standard established a universal method for air-handling unit manufacturers to measure and report the sound levels of their products. Once the industry had a standardized measuring mechanism in place they began designing and building quieter systems that would meet the new, more stringent standards.
Today, acoustic design specialists can help mitigate noise coming from heating and cooling units, traffic, and other external sources. They also work with architects to develop sensible school floor plans. For instance, when designing the layout of a building, architects should avoid placing sensitive classrooms near noisy spaces. Simply by making smart layout choices, many schools can steer clear of expensive sound isolation construction.
Acoustic consultants also look at which way classrooms are facing and how much sound propagates to adjacent rooms. All of these early decisions affect the big picture, which is why it makes sense to involve an acoustic team early in the design process when it’s still cost effective.
Today, architects, engineers, school officials, and private industry are becoming more aware of noise levels outside and inside our children’s classrooms, and increasingly they are seeking out the acoustic expertise required to mitigate the problem. Evolving sets of standards from a variety of sources are changing the way learning happens – and that’s a good thing.