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breebaart2001_preproc - Binaural and monoaural auditory model from Breebaart et. al. 2001

Usage

[ei_map, fc, outsigl, outsigr] = breebaart2001_preproc(insig,fs);
[ei_map, fc, outsigl, outsigr] = breebaart2001_preproc(insig,fs,...);
[ei_map, fc] = breebaart2001_preproc(insig,fs);
[ei_map, fc] = breebaart2001_preproc(insig,fs,...);

Input parameters

`insig`	input acoustic signal.
`fs`	sampling rate.
`tau`	characteristic delay in seconds (positive: left is leading)
`ild`	characteristic ILD in dB (positive: left is louder)

Output parameters

`ei_map`	EI-cell representation
`outsigl`	internal monaural representation of the left ear
`outsigr`	internal monarual respresnetaion of th right ear
`fc`	center frequencies of the filterbank

breebaart2001_preproc(insig,fs,tau,ild) computes the EI-cell representation of the signal insig sampled with a frequency of fs Hz as described in Breebaart (2001) of the signal insig sampled with a frequency of fs Hz. The parameters tau and ild define the sensitivity of the EI-cell.

The input must have dimensions time \(\times \)times ` signal no.

[ei_map,fc]=breebaart2001_preproc(...) additionally returns the center frequencies of the filter bank.

[ei_map,fc,ml,mr]=breebaart2001_preproc(...) additionally returns the center frequencies of the filter bank and the internal monaural representations.

The Breebaart 2001 model consists of the following stages:

an outer and middle ear transfer function
a gammatone filter bank with 1-erb spaced filters.
an envelope extraction stage done by half-wave rectification followed by low-pass filtering to 770 Hz.
an adaptation stage modelling nerve adaptation by a cascade of 5 loops.
an excitation-inhibition (EI) cell model.

Parameters for auditoryfilterbank, ihcenvelope, adaptloop and breebaart2001_eicell can be passed at the end of the line of input arguments.

Examples

The following code sets up a simple test example for the binaural output:

% Setup parameters
fs      = 44100;            % Sampling rate
T       = 0.3;              % Duration
Spl1    = 75;               % SPL of input signal 1
Spl2    = 75;               % SPL of input signal 2
rho     = 0;                % normalized correlation of signals
tau     = 0;
ild     = 0;

% Generate signals:
t  = [0:1/fs:T];
n1 = setdbspl(randn(length(t),1),Spl1);
n2 = setdbspl(randn(length(t),1),Spl2);
x1 = n1*sqrt((1+rho)/2) + n2*sqrt((1-rho)/2);
x2 = n1*sqrt((1+rho)/2) - n2*sqrt((1-rho)/2);

% Run the model and plot it
[ei_map,fc] = breebaart2001_preproc([x1,x2], fs, tau, ild);
plotfilterbank(ei_map,1,fc,fs,'audtick','lin');

References: