Exposure levels, tonal components, and noise annoyance in working environments

Abstract

Noise annoyance and noise exposure were analysed in 439 working places. The investigation included different types of working situations and noise with different frequency characteristics. The study included 235 low-frequency environments, 147 middle-frequency environments, and 57 high-frequency environments. The noise annoyance reactions were studied by means of graphical rating scales. The noise was expressed as dBlin, dB(A), dB(B), dB(C), and dB(D). The noise exposures were also classified, based on 1 3 - octave band analysis, into three classes: exposures without tonal components, exposure with one tone, and several tonal components. Classifications were also made with respect to frequency character and exposure levels. The analyses of dose-response relations between annoyance and noise level showed that dB(A) was neither better nor worse than any of the other alternative weighting methods. The correlations between sound level and annoyance ratings were weak. Annoyance was also influenced by other factors than the noise level. People exposed to noise with tonal components were more annoyed than the others. Rated annoyance was further increased when the noise contained several tones. The frequency characteristics and the sound level of the noise affected the strength of the effect of tones on annoyance. The effect of the tonal component on annoyance corresponded to a difference in pressure level of approximately 6 dB.