fb = hohman2002(fs, flow, basef, fhigh, filters_per_ERBaud)
|fs||The sampling frequency of the signals on which the filterbank will operate|
|flow||The lowest center frequency of a filter|
|basef||"base frequency". One of the filters will have exactly this center frequency. Must be >= flow|
|fhigh||The highest center frequency of a filter. Must be >= basef|
|The density of gammatone filters on the ERB scale.|
|fb||The constructed filterbank object.|
hohman2002 constructs a new fb object implementing the analysis part of a gammatone filterbank as described in Hohmann (2002).
fb contains several all-pole gammatone filters; each one with a bandwidth of 1 ERB (optional: times bandwidth_factor), and an order of gamma_order.
The center frequencies of the individual filters are computed as described in section 3 of Hohmann (2002).
hohmann2002 takes the following flags at the end of the line of input arguments:
|'gamma_order'||The order of the gammatone filters in this filterbank. Default is 4.|
|'bandwidth_factor'||The bandwidth parameter of the individual filters is calculated from the Equivalent Rectangular Bandwidth (ERB) according to equation 14 in Hohmann (2002). ERB is taken from the Glasberg & Moore formula for a specific center frequency (equation 13 in Hohmann (2002)). Using this parameter, it is possible to widen or narrow all filters of the filterbank with a constant bandwidth factor. Default is 1.0|
|'l'||Scaling factor l from Eq. 13 in Hohmann (2002). Default is 24.7.|
|'q'||Scaling factor q from Eq. 13 in Hohmann (2002). Default is 9.265.|
V. Hohmann. Frequency analysis and synthesis using a gammatone filterbank. Acta Acustica united with Acoustica, 88(3):433--442, 2002.