Loudness and noisiness of a repeated impact sound: Results of round robin tests in Japan. (II).

Abstract

This paper reports and discusses the results of the second stage of experiments of a round robin test on the evaluation of impact sounds. Two psychological attributes, loudness and noisiness, were dealt with in this study. The PSE's for both attributes were obtained by using the same experimental procedure.In this study, a repeated impulsive sound whose duration is 3 s at the longest was presented in a diotic listening condition. The results of the study are summarized as follows: 1) The coefficients for linear regressions of PSE on LpE (the frequency-unweighted sound exposure level) were 0.62-0.63 for loudness, while they were 0.93-1.11 for noisiness. This seems to indicate that the time constant for integration of sensation is longer for noisiness than for loudness. 2) For both loudness and noisiness, LpE showed a high correlation with PSE obtained by our experiments, and thus loudness of repeated impulsive sounds might be described by LpE with some modifications, and noisiness can be expressed by LpE with minor modifications. 3) The difference between the results of carrier signals used in this study has little effects on the experimental data.

A New Method for Loudness Evaluation of Noises with Impulsive Components

“…7-s The loudness of repeated impulsive sound was investigated in the second stage. 9 The loudness of a single burst of impulsive sound corresponds well with the sound exposure level (the square-integrated value of sound pressure, which was abbreviated as LpE) in our first stage studyY ,s Neither LAeQ nor Lp~, however, evaluates the loudness of repeated impulsive sound. 9 According to subsequent investigations, the loudness of repeated impulsive sound corresponds rather well with the signal output through a 2TC (Two-Time-Constant) integrator which has a short rise time constant of 100 ms and a long decay time constant of 5 s. 1°,11 It is impossible to use this circuit alone, however, to assess the loudness of sounds having different frequency spectra because the 2TC integrator acts only as a time-weighting circuit.…”