Usage:

[ei_map, fc, outsigl, outsigr] = breebaart2001(insig,fs);
[ei_map, fc, outsigl, outsigr] = breebaart2001(insig,fs,...);
[ei_map, fc] = breebaart2001(insig,fs);
[ei_map, fc] = breebaart2001(insig,fs,...);

Input parameters:

Output parameters:

Description:

breebaart2001(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.

[ei_map,fc]=breebaart2001(...) additionally returns the center frequencies of the filter bank.

[ei_map,fc,ml,mr]=breebaart2001(...) additionally returns the center frequencies of the filter bank and the internal monaural representations.

The model consists of the following stages:

1. an outer and middle ear transfer function
2. a gammatone filter bank with 1-erb spaced filters.
3. an envelope extraction stage done by half-wave rectification followed by low-pass filtering to 770 Hz.
4. an adaptation stage modelling nerve adaptation by a cascade of 5 loops.
5. 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 = scaletodbspl(randn(length(t),1),Spl1); n2 = scaletodbspl(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([x1,x2], fs, tau, ild); plotfilterbank(ei_map,1,fc,fs,'audtick','lin');