ASA 127th Meeting M.I.T. 1994 June 6-10

4pPP17. The pitches of mistuned harmonics.

Dept. of Phys., Michigan State Univ., East Lansing, MI 48824

If a single harmonic of a complex tone is mistuned it can be heard as a separate entity. Pitch matching experiments show that the pitch of a mistuned harmonic does not agree with its frequency. The shift in pitch, caused by the complex context, is an exaggeration of the frequency mistuning. The differential pitch shift, for positive versus negative mistuning, is called the ``split.'' Splits for complex tones with simple spectra were measured by Hartmann and Smith [J. Acoust. Soc. Am. Suppl. 1 85, S109 (1989)]. Experiments reported here, measure splits for complex tones having spectral gaps and other anomalies. Experiments show that splits depend upon partial masking: Components below the mistuned harmonic create large splits; splits increase with increasing stimulus level. Experiments show that splits also depend upon the overall periodicity of the complex: Splits are larger for mistuned harmonics than for nonharmonic interstitials, given identical local spectral environments. Splits are larger for mistuned harmonics with low harmonic number or low fundamental frequency. These observations require revision of the neural timing model for the pitches of mistuned harmonics. [Work supported by the NIDCD, DC00181.]