Simulations of temporal resolution and integration data with a computer model using a modulation filter bank.

Abstract

Temporal resolution and temporal integration in the auditory system, with their conflicting time constants, are often regarded as paradox phenomena. In this study a model is presented for the simulation of a number of temporal resolution experiments (e.g., gap detection, forward masking) and classical test tone integration data (cf. contributions by Dau et al.). The model consists of two major parts. A preprocessing stage that transforms the acoustic stimulus into an internal representation, simulating the peripheral processing in the auditory system. Processing errors are accounted for by adding internal noise which introduces detection limits. The second stage is an optimum detector to simulate a ‘central’ decision device. The preprocessing stage consists mainly of three subunits: a Gamma tone filterbank to simulate peripheral filtering; a set of adaptive feedback loops that derives an adapted envelope of every peripheral filter output; a modulation filterbank (per peripheral channel) that analyzes stimulus periodicities in these adapted representations. The model is able to simulate gap detection and test tone integration experiments quantitatively without changing its parameters. It can be shown that within this model the modulation filterbank is vital to achieve this performance. [Supported by the DFG (Az. Mu/1201).]