DAU96 - Auditory model from Dau et. al. 1996.

Usage:
  • [outsig, fc] = dau96(insig,fs,flow,fhigh);
  • [outsig, fc] = dau96(insig,fs,flow,fhigh,basef);
Input parameters:
  • insig: input acoustic signal.
  • fs: sampling rate.
  • flow: lowest filter center frequency.
  • fhigh: highest filter center frequency.
  • basef: Always include this frequency in the filter bank (optional).

Description:

DAU96(insig,fs,flow,fhigh) computes the internal representation of the signal insig sampled with a frequency of fs Hz as described in Dau, Puschel and Kohlrausch (1996a). The parameters flow and fhigh determine the lowest and highest frequencies in the filter bank. The filters are spaced 1 Erb apart

DAU96(insig,fs,flow,fhigh,basef) does the same, but ensures that the frequency basef is one of the frequencies in the filter bank.

DAU96(insig,fs) chooses the lowest frequency to be 80 and the highest to be 8000.

[outsig,fc]=DAU96(...) additionally returns the center frequencies of the filter bank.

The model assumes than an input signal with an RMS value of 1 corresponds to an acoustic signal of 100 db SPL.

The dau96 model consists of the following stages:

* a gammatone filter bank with 1
* an envelope extraction stage done by half followed by low-pass filtering to 1000 Hz.
* an adaptation stage modelling nerve adaptation by a cascade of 5 loops.
* a modulation low pass filter liming modulations to below 50 Hz.


The model implemented in this file is not identical to the model published in Dau et. al. (1996a). An overshoot limit has been added to the adaptation stage to fix a problem where abrupt changes in the input signal would cause unnaturally big responses. This is described in Dau et. al. (1997a).

References:

T. Dau, D. Püschel, and A. Kohlrausch. A quantitative model of the effective signal processing in the auditory system. I. Model structure. The Journal of the Acoustical Society of America, 99(6):3615-3622, 1996a.

T. Dau, D. Püschel, and A. Kohlrausch. A quantitative model of the effective signal processing in the auditory system. II. Simulations and measurements. The Journal of the Acoustical Society of America, 99:3623, 1996b.

T. Dau, B. Kollmeier, and A. Kohlrausch. Modeling auditory processing of amplitude modulation. I. Detection and masking with narrow-band carriers. The Journal of the Acoustical Society of America, 102:2892, 1997a.