Temporal averaging of subjective magnitude and proposed rating scale for fluctuating noise

Abstract

A method for predicting the effective sound level (ESL) is proposed in this paper. The effective sound level is the sound level of a steady noise which produces the same subjective magnitude as a fluctuating noise and may be measured as the point of subjective equality by means of psychometric methods. The proposed method gives the predicted value of ESL which is denoted as Leff, based on an assumption of integration and averaging of subjective magnitude. It has been shown that Leff can be expressed by an equation which contains the probability density function of the level distribution and two empirical parameters, the values of exponents for sound pressure and duration in the psychophysical function. The practical significance of the descriptor Leff was discussed in terms of the definition of the number of events. High correlation between Leff and the subjects’ response was found.