RESPITE: The CASA Toolkit Page: Documentation: Block Library Index:GammatoneBank


The GammatoneBank implements a bank of gammatone filters. The number of filters in the bank is given by the parameter NUM_CHANS. These filters are arranged on either an ERB, a Mel, or a linear scale between a lower and upper centre frequency given by the parameters LOWER and UPPER respectively.

For every sample arriving at the input a vector of dimensionality NUM_CHANS is produced at each of the four output sockets. The vector output at out1 samples the instantaneous envelope for each channel; out2 is a simulation of basilar membrane displacement; out3 if the instantaneous frequency and out4 is the amplitude modulation frequency.

Inputs Meaning Sample 1-D frame $\ge$2-D frame
in1 input sample data Yes No No

Outputs Meaning
out1 instantaneous envelope
out2 basilar membrane displacement
out3 instantaneous frequency
out4 AM frequency

Parameters Type Default Meaning
NUM_CHANS Integer 64 Number of gammatone filter channels
LOWER Float 50.0 Centre frequency of lowest frequency channel
UPPER Float 5000.0 Centre frequency of highest frequency channel
SCALE {ERB, MEL, LINEAR} ERB The frequency scale on which to space the filters

Documentation for CTKv1.1.4 - Last modified: Thu Jun 28 11:47:01 BST 2001