In-Channel Cancellation
Résumé
Abstract A model of early auditory processing is proposed in which each peripheral channel is processed by a delay-and-subtract cancellation filter, tuned independently for each channel with a criterion of minimum power. For a channel dominated by a pure tone or a resolved partial of a complex tone, the optimal delay is its period. For a channel responding to harmonically-related partials, the optimal delay is their common fundamental period. Each peripheral channel is thus split into two subchannels, one cancellation-filtered and the other not. Attention can be directed to either depending on the task. The model is applied to explain the masking asymmetry between pure tones and noise: a noise target masked by a tone is more easily detectable than a tone target masked by noise. The model is one of a wider class of models, monaural or binaural, that cancel irrelevant stimulus dimensions so as to attain invariance to competing sources. Similar to occlusion in the visual domain, cancellation yields sensory evidence that is incomplete, thus requiring Bayesian inference of an internal model of the world along the lines of Helmholtz’s doctrine of unconscious inference.
Domaines
Sciences cognitivesOrigine | Fichiers produits par l'(les) auteur(s) |
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