Pitch discrimination interference (PDI) refers to an impairment in the ability to discriminate changes in the fundamental frequency (F0) of a target harmonic complex, caused by another harmonic complex (the interferer) presented simultaneously in a remote spectral region. So far, PDI has been demonstrated for target complexes filtered into a higher spectral region than the interferer and containing no peripherally resolved harmonics in their passband. Here, it is shown that PDI also occurs when the target harmonic complex contains resolved harmonics in its passband (experiment 1). PDI was also observed when the target was filtered into a lower spectral region than that of the interferer (experiment 2), revealing that differences in relative harmonic dominance and pitch salience between the simultaneous target and the interferer, as confirmed using pitch matches (experiment 3), do not entirely explain PDI. When the target was in the higher spectral region, and the F0 separation between the target and the interferer was around 7% or 10%, dramatic PDI effects were observed despite the relatively large F0 separation between the two sequential targets (14%-20%). Overall, the results suggest that PDI is more general than previously thought, and is not limited to targets consisting only of unresolved harmonics.
Bibliographical noteFunding Information:
This work was supported by the National Institutes of Health (NIDCD Grant R01 DC 05216) and was completed while the authors were in the Research Laboratory of Electronics at the Massachusetts Institute of Technology. The authors are grateful to Hedwig Gockel for the time taken in helping to improve the clarity and presentation of this manuscript. Alain de Cheveigné, John Grose, and an anonymous reviewer also provided helpful comments on earlier versions of the manuscript.