Shigeaki Aoki
NTT Human Interface Labs., 1-2356, Take Yokosuka-shi, Kanagawa 238-03, Japan
Tammo Houtgast
TNO Inst. for Human Factors, Soesterberg, The Netherlands
The total perception for pitch and loudness as a function of level difference between the leading and trailing stimuli is investigated using the same stimulus configuration and measuring the paradigm which clearly showed that the dominance of the leading stimulus depends on the level difference [S. Aoki and T. Houtgast, Hear. Res. (1992)]. A brief stimulus of 20 ms is subdivided into two parts with durations T[sub 1] and T[sub 2]. Each part consists of a sinusoidal signal of either 1 or 2 kHz for pitch perception, or each part consists of a 2-kHz sinusoidal signal with either + or -3 dB for loudness perception. The measuring paradigm aims at assessing the critical ratio T[sub 1]/T[sub 2] for which both parts contribute equally to the overall sensation of pitch or loudness for these brief stimuli. In contrast to the earlier study on dichotic cues, the effect of the level difference between the leading and trailing stimuli on pitch perception is found to be smaller and discontinuous. The effect on loudness perception is found to be greater and symmetrical. It is also found that the characteristic curves of these perceptions form a meaningful triangular area.