DIETZ2011_FILTERBANK - filterbank of Dietz 2011 binaural model

Usage:

[...] = dietz2011_filterbank(insig,fs,fc);

Input parameters:

`insig`	binaural signal for which values should be calculated
`fs`	sampling rate (Hz)
`fc`	center frequencies of gammatone filterbank

Output parameters:

`outsig_fine`	output signal of fine structure filter
`fc_fine`	center frequencies processed with fine structure filter
`outsig_env`	output signal of envelope filter
`fc_env`	center frequencies processed with modulation filter
`outsig_ild`	output signal of ILD filter

Description:

dietz2011_filterbank(insig,fs,fc) filters all frequency channels of insig with a modulation filterbank consisting of three filters. One centered at the center frequencies for the fine structure of the signals. One centered at a fixed frequency of 135 Hz for the envelope of the signals. And one a lowpass filter with a cutoff frequency of 30 Hz for the calculation of the interaural level difference.

dietz2011_filterbank accepts the following optional parameters:

`'filter_order',fo`	Filter order for the two gammatone filter used for the fine structure and envelope of the modulation filter bank. The default value is 2.
`'filter_attenuation_db',fadb`
	Filter attenuation for the two gammatone filter used for the fine structure and envelope of the modulation filter bank. The default value is 10.
`'fine_filter_finesse',fff`
	Filter finesse (determines the bandwidth with fc/finesse) for the fine structure gammatone filter. The defulat value is 3.
`'mod_center_frequency_hz',mcf_hz`
	Center frequency of the gammatone envelope filter. The default value is 135.
`'mod_filter_finesse',mff`
	Filter finesse (determines the bandwidth with fc/finesse) for the envelope gammatone filter. The defulat value is 8.
`'level_filter_cutoff_hz',lfc_hz`
	Cutoff frequency off the low pass filter used for ILD calculation. The default value is 30.
`'level_filter_order',lforder`
	Order of low pass filter for the ILD calculation. The default value is 2.

References: