This study investigated the relationship between harmonic frequency resolution and fundamental frequency (f0) discrimination. Consistent with earlier studies, f0 discrimination of a diotic bandpass-filtered harmonic complex deteriorated sharply as the f0 decreased to the point where only harmonics above the tenth were presented. However, when the odd harmonics were mistuned by 3%, performance improved dramatically, such that performance nearly equaled that found with only even harmonics present. Mistuning also improved performance when alternating harmonics were presented to opposite ears (dichotic condition). In a task involving frequency discrimination of individual harmonics within the complexes, mistuning the odd harmonics yielded no significant improvement in the resolution of individual harmonics. Pitch matches to the mistuned complexes suggested that the even harmonics dominated the pitch for f0 's at which a benefit of mistuning was observed. The results suggest that f0 discrimination performance can benefit from perceptual segregation based on inharmonicity, and that poor performance when only high-numbered harmonics are present is not due to limited peripheral harmonic resolvability. Taken together with earlier results, the findings suggest that f0 discrimination may depend on auditory filter bandwidths, but that spectral resolution of individual harmonics is neither necessary nor sufficient for accurate f0 discrimination.
Bibliographical noteFunding Information:
This work was supported by NIH Grant No. R01 DC 05216, and was carried out while both authors were at the Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA. The authors thank Christophe Micheyl, Van Summers, three anonymous reviewers, and the associate editor, Richard Freyman, for providing helpful comments on an earlier version of the manuscript. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or Department of Defense. 1