A Consideration of the Relationship between Subjective Unpleasantness and Body Surface Vibrations Induced by High-Level, Complex Low-Frequency Noise

Abstract

To investigate the relationship between subjective unpleasantness and body surface vibrations induced by high-level, complex low-frequency noise, we carried out two expetiments. Body surface vibrations were measured at the right and left anterior chest and the right and left anterior abdomen of male subjects. Subjective unpleasantness was rated on a scale of 1 to 5, and correlated with the vibration acceleration levels (VALs) of the vibrations measured on the body surface. As a result, it was found that the ratings of unpleasantness did, on the whole, significantly correlate with the VALs. In addition, we estimated the frequency-weightings for the VAL to optimize the correlation with the rating of unpleasantness. Based on a reasonable hypothesis, the frequency-weightings estimated in the present study were considered to be consistent with those estimated in our previous study using low-frequency pure tones. The present results support the idea that not only the loudness of a noise, but also the vibrations induced by that noise, contribute to the subjective unpleasantness experienced by persons exposed to high-level low-frequency noise. The effect of vibration should be taken into consideration in evaluating high-level low-frequency noise.