Subjective evaluation test on the effect of tonal components on broadband noise

Abstract

Environmental noise sometimes contains tonal components, and it has been pointed out that this can be responsible for increasing the annoyance of noise. In Japan, noise problems related to tonal noises generated from wind turbines and heat pump systems have recently been occurring. To solve the noise problem, it is necessary to quantitatively understand the effect of tonal components on noise annoyance. In this study, annoyance evaluation experiments were conducted using broadband noise containing a tonal component. Four types of noise were used for the auditory test: white noise, pink noise, and low-frequency prominent noise that simulated indoor- and outdoor environmental noise. The frequencies of tonal components added to the broadband noise were from 50 to 2000 Hz, with intensities where the tonal audibility was 0, 5, 10, and 15 dB. The results show that the annoyance increases with the intensity of the tonal component, but the amount of increase depends on the frequency characteristics of the background noise and the tonal frequency. This increase in annoyance was quantified as a penalty in A-weighted sound pressure level.