by Ben Markham, LEED AP
It is intuitive the acoustical environment plays a key role in the wellness, education, and productivity of building occupants. After all, mankind only has the benefit of eyelids, and not “earlids;” one can avert the gaze, but not hearing. Sound is all around, and the acoustical environment impacts everyone, whether consciously or not.
How many times do guests wake up in a hotel room because of the TV next door, the traffic outside, or the door slamming down the hall?
In the workplace, research on productivity and “deep work” demonstrates the benefits of distraction-free environments, just as economic realities are forcing ever-greater density in office spaces. In hospitals, the healing benefits of rest and sleep are increasingly recognized in building design. Control over extraneous noise is a key component of current healthcare design guidelines. In the classroom, low noise and high speech intelligibility lead to greater learning outcomes.
Building design standards, such as the General Services Administration’s (GSA’s) P-100, Facilities Standards, and Facility Guidelines Institute’s (FGI’s) healthcare design guideline recognize the necessity of good acoustical design. Acoustics-related credits are also offered by sustainability scorecards from the Leadership
in Energy and Environmental Design (LEED), WELL, and Collaborative for High Performance Schools (CHPS) programs.
With good design and thoughtful planning, building acoustics can work very much to one’s advantage, enabling communication across the classroom, collaboration in the lab, privacy in the workplace, and a good night’s sleep.
What matters acoustically is not (just) how loud something is but how loud that something is relative to the background sound. If high speech intelligibility is the goal, one must design for a high signal-to-noise ratio, meaning the speech (signal) should be nice and loud in comparison to the background sound (noise), which should be kept quiet. By contrast, if the design goal is speech privacy (e.g. confidentiality between patient rooms or law offices), the signal-to-noise ratio should be low—the loudness of speech coming from “next door” (signal) should be kept quiet, relative to the background sound in the observer’s room.
Good acoustical design intentionally crafts the architectural environment and the building systems to optimize the signal-to-noise ratio based on the programmed uses, rather than leaving acoustical character to happenstance.
There are three main areas of architectural acoustics design:
- building system noise and vibration control;
- sound isolation; and
- room acoustics.
A fourth area—sound system design—is related and can be important for many spaces, whereas the first three—the focus of this article—are worth careful consideration in nearly all architectural environments.