Noise-induced shifts in the pitch of pure and complex tones

Abstract

The influence of masking noise on the pitch of dichotic two-tone complexes and on the pure-tone pitches of their spectral components is investigated by matching both to the pitch of a binaural periodic pulse comparison signal. It is found that noise-induced shifts in the pitch of pure tones are considerably larger than induced shifts in complex tone or ’’residue’’ pitch. A pitch matching experiment with pure tones and contralateral noise reveals a general, central effect of noise on pitch. If empirical pitch matching data are corrected for this central effect, complex-tone pitch is found to be independent of the influence of masking noise, whereas pure-tone pitch remains subject to significant induced shifts. This finding is inconsistent with some of the modern pitch theories. It is consistent with the notion that pure-tone pitch is mediated by spatial, and complex-tone pitch by temporal encoding in peripheral auditory units.