ABSTRACT
When a single low partial in a harmonic complex tone is shifted progressively in frequency from its harmonic value, the pitch of the whole complex (residue pitch) shifts with it, in a proportional manner, until the shift exceeds a certain value. Beyond that, the pitch shift is less than proportional and eventually declines. The mechanism determining the pitch of complex tones apparently rejects components which are sufficiently mistuned. A component which is sufficiently mistuned also tends to be heard as a separate component, standing out from the complex as a whole. The present paper considers whether these two perceptual effects reflect the same underlying process. Thresholds for hearing a mistuned harmonic as standing out from a complex tone decrease as the duration of the stimulus increases. The degree to which a partial can be mistuned before it makes a reduced contribution to residue pitch also decreases with increasing duration, but not to the same extent. For long-duration tones and for moderate degrees of mistuning (3–4%) the mistuned harmonic is clearly heard as a separate tone, but at the same time it can make a strong contribution to the pitch of the complex as a whole, indicating a form of “duplex perception”. Finally, it is demonstrated that, when subjects compare the pitches of complex tones with common harmonics, they do not simply compare the pitches of individual components; rather, judgements are made on the basis of residue pitch.
