Why pitch strength decreases with increasing harmonic number in complex tones

Abstract

A melodic pitch experiment was performed to demonstrate the importance of temporal resolution for pitch salience. The experiments show that notes with a low fundamental (75 Hz) and relatively few resolved harmonics support better performance than comparable notes with a higher fundamental (300 Hz) and more resolved harmonics. Two four-note melodies were presented to listeners and one note in the second melody was changed by one or two semitones. Listeners were required to identify the note that changed. There were four orthogonal stimulus dimensions: F0 (75 and 300 Hz), lowest frequency component (3, 7, 11, or 15), number of harmonics (2, 4, or 8), and degree of component rove (1 or 3). Performance decreased as the frequency of the lowest component increased for both F0s, but performance was better for the lower F0. The spectral and temporal information in the stimuli were compared using the Auditory-Image Model [Bleeck et al., Acta Acust. 90, 781–788 (2004)]. Peaks in the time-interval profile of the auditory image can explain the decrease in performance as F0, and spectral resolution increase. Spectral profiles of the same auditory images do not contain sufficient resolution to explain the performance. [Work supported by U.K. MRC (G0500221, G9900369).]