Frequencies Dominant in the Perception of the Pitch of Complex Sounds

This paper deals with measurements carried out with pulsive signals to determine the spectral region associated with dominant pitch perception. The stimulus consisted of the sum of (1) a low-frequency band of a unipolar pulse train with fundamental frequency f0 (or f0+Δf) and upper cutoff frequency fe and (2) a high-frequency band of a unipolar pulse train with fundamental frequency f0+Δf (or f0) and lower cutoff frequency fe. In the experiments f0 was 100, 200, and 400 Hz, respectively; Δf/f0 was either 3% or 6%; and over-all sensation level was between 30 and 50 dB. When the fundamental frequencies were interchanged, a pitch change “up” or “down” was heard, depending on the “crossover” frequency fe. For fe larger than the sixth harmonic, the low-frequency band always dominated the pitch percept. Changing the sensation level of the low-frequency band with respect to the higher-frequency band, the minimum sensation level for dominant pitch perception was determined. It was found that, for a given fe, the low band tended to dominate the pitch perception as long as its amplitude exceeded a minimum absolute level. Dominance was found to be independent of Δf. By selectively limiting the number of components in the low-frequency band, the spectral region dominant for the perception of pitch was determined more precisely. This spectral region covered the frequency band consisting of the third, fourth, and fifth harmonics for signals with fundamental frequencies in the range of 100–400 Hz.