By Niklas Moeller and Viken Koukounian, PhD, P.Eng.
While sight is generally prioritized over other sensory modalities during building design, a completed structure’s aural qualities do not simply provide a neutral backdrop for activities—a fact apparent to those who managed to carve out “quieter” home offices during the pandemic, only to be called back to noisy, overstimulating commercial and public spaces.
During the intervening pandemic period, many employees also began paying greater attention to their personal wellbeing, intensifying expectations for healthy workspaces. Although the workplace category remains the slowest growing within a projected USD $7 million world wellness market by 2025, the Global Wellness Institute (GWI) attributes this lag to the shift organizations are finally making from compartmentalized wellness programs aimed at treating symptoms—such as stress, disengagement, and absenteeism—to more holistic and proactive approaches that tackle problems at their source by, for example, leveraging workplace design.
To tap into the built environment’s full potential to improve wellbeing, one needs to better understand not only how noise negatively affects occupants’ physical and mental health, but the ways in which “the sonic aspect of buildings can be intentionally articulated to achieve a richer, more satisfying built environment: one that responds to the ear as well as the eye.”1
Auditory health effects
Hearing is a historically undervalued and underserved sense, at least within Western societies. It was not until the mid-20th century—as public awareness of the need for stricter occupational health and safety guidelines grew—that the requirement to preserve it garnered widespread support. Numerous studies subsequently demonstrated strong correlations between sudden or sufficiently prolonged exposure to higher noise levels and temporary or permanent hearing loss, which is generally understood to mean damage to the hairs or nerve cells within the ears, affecting their ability to transmit information to the brain. Other potential consequences may involve tinnitus, characterized by ringing or other “phantom noises” in the ears, and hyperacusis, which refers to the increased sensitivity to ordinary sounds.
Today, most people are well-acquainted with the auditory health effects of high noise levels, as well as the associated “safe limits” established for workplaces. Basically, the risk of hearing loss is immediate when the noise level approaches or exceeds 120 decibels (dB) (e.g. from an explosion), while impairment due to lower levels (e.g. from machinery) usually requires longer exposure; for example, a 15-minute exposure to 100 dB or a two-hour-long exposure to 90 dB.2 In the U.S., the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) is 85 A-weighted decibels (dBA) averaged over an eight-hour work shift.3 As noise increases above that level, the allowed exposure time decreases.
