Phase effects in a three-component signal.

Abstract

Phase effects in a particular three-component signal, consisting of the 9th, 10th, and 11th harmonic of 200 Hz were studied. The main interest was the effect of phase changes on the prominence of the residue pitch evoked by this signal. The prominence of residue pitch appears to be correlated to the acoustical power spectrum of the signal, modified by the internally generated combination tones. An estimate of this “internal spectrum” was obtained by means of a cancellation technique. Because of an interaction of combination tones and acoustical components, this “internal spectrum” is phase-dependent. In this context de Boer's phase rule is reconsidered. The residue pitch seems to be most prominent if there are prominent lower harmonics in the “internal spectrum.” In general, subjective phase effects in this signal, which could be described as changes in timbre, seem to be dependent on changes in the “internal spectrum.”