Effects of building mechanical system noise on worker performance and perception.

Abstract

This paper presents results from a number of studies that investigated the effects of noise from building mechanical systems on human task performance and perception. Three phases of research were conducted, each of which utilized a different set of noise signals produced by building mechanical systems: (1) broad-band noise at different levels and spectral qualities, (2) tonal noise conditions, and (3) noise conditions with time-varying fluctuations. In each phase, six different noise signals (many based on in-situ measurements) were reproduced in an office-like setting. Thirty participants completed tasks (e.g., typing, grammatical reasoning, and math) plus subjective questionnaires, while exposed to each noise condition for up to 1 h. In general, no statistically significant differences were found in task performance across the various noise signals tested. However, higher annoyance/distraction responses from the test subjects were often significantly correlated with reduced typing performance. These higher annoyance/distraction responses were also closely correlated to higher subjective ratings of loudness, followed by roar, rumble, and tones or fluctuations. Of particular interest is that a greater perception of low-frequency rumble was significantly linked to reduced performance on both the routine and cognitively demanding tasks. [Work supported by the American Society of Heating, Refrigeration and Air-Conditioning Engineers.]