抄録
This paper discusses multidimensional perceptual space derived from the results of psychoacoustical experiments on similarities in the quality of sounds amplitude-modulated by nine triangular waves different in rise- and fall-times. For sinusoidal (1 kHz) and random-noise carriers, three experiments were conducted with different modulation frequencies, namely 8, 16 and 32 Hz. In each experiment, similarities in sound quality for stimuli with modulation depths of 0.4, 0.8 and 1.0, as well as the original carrier wave, were rated. The similarities were analyzed by a multidimensional scaling method (ALSCAL), and three-dimensional configurations were derived. A common configuration correlated with the modulation depth was seen irrespective of carrier wave and modulation frequency. There was a perceptual dimension related to shape of amplitude modulation for all conditions except for noise carrier with 32-Hz modulation. The difference in rise time caused larger differences in sound quality than similar differences in fall time up to a modulation frequency of 16 Hz, irrespective of the kind of carrier wave.
