title: Dichotic pitches as illusions of binaural unmasking. II. The Fourcin pitch and the dichotic repetition pitch.
abstract: The predictions of three models are compared with respect to existing experimental data on the perception of the Fourcin pitch (FP) and the dichotic repetition pitch (DRP). Each model generates a central spectrum (CS), which is examined for peaks at frequencies consistent with the perceived pitches. A modified equalization-cancellation (mE-C) model of binaural unmasking [Culling and Summerfield, J. Acoust. Soc. Am. 98, 785-797 (1995)] generates a CS which reflects the degree of interaural decorrelation present in each frequency channel. This model accounts for the perceived frequencies of FPs, but produces no output for DRP stimuli. A restricted equalization-cancellation (rE-C) model [Bilsen and Goldstein, J. Acoust. Soc. Am. 55, 292-296 (1974)] sums the time-varying excitation in corresponding frequency channels, without equalization, to form a CS. A central activity pattern (CAP) model [Raatgever and Bilsen, J. Acoust. Soc. Am. 80, 429-441 (1986)] generates a CS by scanning an interaural cross-correlation matrix across frequency. The rE-C and CAP models yield inaccurate predictions of the perceived frequencies of FPs, but predict the occurrence of the DRP and its correct pitch. The complementary predictions of the mE-C model compared to the rE-C and CAP models, together with the evidence that the FP is clearly audible for the majority of listeners, while the DRP is faintly heard by a minority of listeners, suggest that the mE-C model provides the best available account of the FP, and that the DRP is produced by a separate mechanism.
authors.affiliation: MRC Institute of Hearing Research, University of Nottingham, United Kingdom.
authors.forename: J F
authors.initials: JF
authors.lastname: Culling
authors.forename: D H
authors.initials: DH
authors.lastname: Marshall
authors.forename: A Q
authors.initials: AQ
authors.lastname: Summerfield
mesh_terms: D004007:Dichotic Listening Tests; D006801:Humans; D008954:Models, Biological; D009622:Noise; D010470:Perceptual Masking; D010898:Pitch Perception / Q000502:physiology*; D013997:Time Factors