Annoyance and Low Frequency Noise with Different Slopes of the Frequency Spectrum

Abstract

Twelve subjects matched a band noise (900–1060 Hz) to equal the annoyance of low frequency noises with three different fall-off rates (slopes) of energy above 125 Hz (−3, −6 and −9 dB I octave) at two levels. Furthermore, subjects rated annoyance on a graphic rating scale. According to Bryan (1976) a decreased slope should lead to a lowered annoyance response. This was not confirmed, both the matching and rating data showed that annoyance increased with decreasing slope. The unit dB(A) was found to underestimate and dB(C) to overestimate annoyance especially for the noises with the steeper slope, dB(B), dB(D) and PhondB were found to assess all noises fairly adequately.