EXPOSURE LEVELS, TONAL COMPONENTS, AND NOISE ANNOYANCE IN WORKING ENVIRONMENTS

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 23 5 low-frequency environments, 147 middle-frequency environments, and 5 7 high-frequency environments. The noise annoyance reactions were stud ied by means of graphical rating scales. The noise was expressed as dB Iin, dB(A), dB(B), dB(C), and dB(D). The noise exposures were also cla ssified, based on 1/3-octave band analysis, into three classes: exposu res without tonal components, exposure with one tone, and several tona l components. Classifications were also made with respect to frequency character and exposure levels. The analyses of dose-response relation s between annoyance and noise level showed that dB(A) was neither bett er nor worse than any of the other alternative weighting methods. The correlations between sound level and annoyance ratings were weak. Anno yance was also influenced by other factors than the noise level. Peopl e exposed to noise with tonal components were more annoyed than the ot hers. Rated annoyance was further increased when the noise contained s everal 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 differenc e in pressure level of approximately 6 dB.