A growing body of literature dealing with the non-auditory effects of lower-level noise differentiates between “noise exposure” and “noise sensitivity.” In a review, Brown et al. cites Schreckenberg et al., who found that noise affects different people differently, as well as Shepard et al., who “found noise level does not necessarily determine noise annoyance, but rather other factors play a role, in particular, noise sensitivity.”4 The findings presented by Park et al. (2017)—in a paper titled “Noise sensitivity, rather than noise level, predicts the non-auditory effects of noise in community samples: a population-based survey”—show the effects, specifically those pertaining to mental well-being on an individual’s health are more strongly correlated with their sensitivity to noise than other variables (e.g. sociodemographic factors, medical illness, duration of residence, and so on).
Although the focus of such research largely remains an assessment of the person, (a comprehensive description of the acoustic conditions is seldom provided), distinguishing between noise exposure and noise sensitivity has advanced understanding of the non-auditory effects of noise and led more researchers to question whether different people react similarly—or the extent to which they do—when exposed to lower-level sources, and to focus on the psychological, as well as the physical, impacts.
Neurodiversity and noise
Researchers are also exploring how differences come into play within the workplace. For example, neurological differences—such as autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), dyslexia, and dyspraxia, as well as neurological challenges resulting from brain injury—can impact how individuals process sensory information (e.g. increase noise sensitivity), which in turn affects their social and occupational functioning. Employees can also suffer from misophonia, or other auditory hypersensitivities, whereby common sounds such as chewing, breathing, and repetitive tapping—or stimuli related to such sounds—elicit a strong emotional response ranging from mild irritation to anxiety, anger, disgust, and even significant distress.
While offering privacy pods and headsets might seem like relatively simple solutions, these tactics may not send the desired message of inclusivity or be the most sustainable given neurominorities already comprise 15 to 20 per cent (some posit as high as 40 per cent) of the population, and that figure is expected to rise in the coming years.5, 6 More holistic approaches to acoustical design will not only better accommodate increasing numbers of neurodiverse individuals, they will also greatly benefit those considered neurotypical because no one is immune to environmental stressors and, particularly, to noise.
POEs highlight ‘poor acoustics’
Indeed, post-occupancy evaluations (POE) such as those conducted by the Center for the Built Environment (CBE) show that “poor acoustics”—predominantly lack of speech privacy and noise from conversation—consistently ranks as the top source of workplace dissatisfaction. Parkinson et al.’s recent in-depth analysis of more than 600 office buildings with 62,000 occupants in the CBE’s database reveals that, of all sources of dissatisfaction, acoustics most strongly interferes with self-reported work performance—a conclusion supported by numerous studies demonstrating its negative impact on focus.7 The associated productivity losses due to increased errors and time spent on tasks, as well as reduced capacity for creativity, innovation, and problem solving are also well documented, as are the detrimental effects on collaboration due to fear of being overheard and disrupting others, as well as increased use of electronic communication, headsets, and requests to work remotely.
“Poor acoustics” also takes a psychological and physical toll on employees, who report feeling uncomfortable, edgy, irritable, and unmotivated in noisy workspaces. By stimulating the sympathetic nervous system (i.e. the “fight-or-flight” response), noise can have cardiovascular-, gastric-, endocrine-, and immune-related impacts. The attempts to overcome this constant environmental stimulus causes cognitive strain and stress, contributing to mental health issues such as anxiety and burnout, which can, in turn, make people even more sensitive to acoustical disturbances. Since people are typically an organization’s largest cost, one must also consider the financial impact of workforce “unwellness”—including stress, disengagement, and illness—which the Global Wellness Institute (GWI) estimates may cost the global economy 10 to 15 per cent of economic output annually.
Workplace design that respects rather than challenges the senses by, for example, mitigating disruptive noise, supports the health and well-being of all an organization’s members and allows everyone to achieve their full potential. In other words, it is not only “neurodiverse design,” but also considered “good design.”8
