1998/06/01 by John F. Culling, A. Quentin Summerfield, David H. Marshall · 3 citations
Computer Science · #Music Technology and Sound Studies
paper · doi:10.1121/1.423059
openalex publication_date 1998/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The two most salient dichotic pitches, the Huggins pitch (HP) and the binaural edge pitch (BEP), are produced by applying interaural phase transitions of 360 and 180 degrees, respectively, to a broadband noise. This paper examines accounts of these pitches, concentrating on a "central activity pattern" (CAP) model and a "modified equalization-cancellation" (mE-C) model. The CAP model proposes that a dichotic pitch is heard at frequency f when an individual across-frequency scan in an interaural cross-correlation matrix contains a sharp peak at f. The mE-C model proposes that a dichotic pitch is heard when a plot of interaural decorrelation against frequency contains a peak at f. The predictions of the models diverge for the BEP at very narrow transition bandwidths: the mE-C model predicts that salience is sustained, while the CAP model predicts that salience declines and that the dominant percept is of the in-phase segment of the noise. Experiment 1 showed that the salience of the BEP was sustained at the narrowest bandwidths that could be generated (0.5% of the transition frequency). Experiment 2 confirmed that the pitch of a BEP produced by a 0.5% transition bandwidth was close to the frequency of the transition band. Experiment 3 showed that pairs of simultaneous narrow 180-degree transitions, whose frequencies corresponded to vowel formants, were perceived as the intended vowels. Moreover, the same vowels were perceived whether the in-phase portion of the noise lay between the two transition frequencies or on either side of them. In contrast, different patterns of identification responses were made to diotic band-pass and band-stop noises whose cutoff frequencies corresponded to the same formants. Thus, the vowel-identification responses made to the dichotic stimuli were not based on hearing the in-phase portions of the noise as formants. These results are not predicted by the CAP model but are consistent with the mE-C model. It is argued that the mE-C model provides a more coherent and parsimonious account of many aspects of the HP and the BEP than do alternative models.