Edge pitches of complex tones obtained at high frequencies

Abstract

The upper edge pitch of harmonic complex tones was matched by adjusting the frequency of a sinusoidal comparison tone. Complexes with upper-edge frequencies between 2 and 8 kHz and fundamental frequencies of 50, 100, and 200 Hz were synthesized by adding all harmonics with equal amplitudes and with zero phases. Tones and intertone gaps had durations of 500 ms. Stimuli were presented diotically through Etymotic ER-2 insert earphones at a sound-pressure level of 60 dB. Five subjects performed ten matches for each complex, from which the standard deviation (s.d.) was calculated and expressed as percentage of the edge frequency. The s.d. generally increased with the edge frequency and with the fundamental frequency. For 50-Hz fundamental, the s.d. was only a factor two larger than in a sine-on-sine match, and four of the five subjects could perceive the edge pitch up to 8 kHz. For higher fundamental frequencies, more and more subjects lost the pitch percept at high edge frequencies, and for 200 Hz only one subject consistently matched the edge pitch at 8 kHz. The results emphasize the role of temporal processes in the perception of edge pitch as well as the importance of phase locking at the frequency of the edge component.