Abstract:
It is necessary to discuss comprehensively effects of low-frequency noise (LFN) on different kinds of modalities by extracting multidimensional bases of evaluation in order to clarify the characteristics of human sensation for LFN, because humans have no sense organ singularly specialized for LFN. In previous research, it was confirmed that there were three main factors of psychological evaluation of LFN by the method of factor analysis: loudness, oppression, and vibration. The purpose is to formulate the relation between physical stimuli and psychological evaluation for LFN by introducing structural relationships and using a multivariate technique to access causations and correlations. The method uses psychophysical experiments and statistical analysis. Pure sine-wave stimuli in 22 conditions were radiated with a frequency from 3 to 40 Hz, and sound-pressure level from 70 to 125 dB. Subjects evaluated the stimuli for the 22 psychological indices by psychophysical methods. Structures among the physical stimuli and psychological evaluation are examined by covariance structure analysis. As for the results, structural covariance models are derived which include observed variables of physical stimuli and psychological evaluation for LFN and latent variables of loudness, oppression, and vibration, which show the causal characteristics of sensation for LFN.