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Bandwidth modes

The bandwidth mode defines the bandwidth of each filter specified by the centre frequency mode. It is implemented in the same way as the centre frequency mode, so any readers who require more detail concerning the implementation should familiarise themselves with the description given above for the centre frequency modes. In figure [27] the bandwidth mode specification occurs on line 4 for parameter file (A) and line 6 for parameter file (B).

The available bandwidth modes are given below in table [3]. The bandwidth's are controlled by the UtBandwidth utilities module.

Mode

Description
Required Parameters
ERB
Equivalent rectangular bandwidths (Glasberg & Moore, 1990).
None.
CAT
Bandwidth formula, fitted from experimental data (Kiang et al., 1965).
None.
GUINEA_PIG
Bandwidth formula, fitted from unpublished data from Alan Palmer (Nottingham).
None.
NONLINEAR
Bandwidth formula, defined by the fitting of the DRNL non-linear filter (paper in preparation).
None.
USER
Custom bandwidths specified by the user.
(..) Bandwidth list - one line for each bandwidth (Hz). The number of lines must correspond with the number of filter-bank output channels specified for the CF mode.
INTERNAL
Bandwidths are defined by the respective basilar membrane module.
None.

Table [3]: The bandwidth modes available for the basilar membrane filter modules.

The bandwidths, except for in the "USER" mode, are produce by a formula which relates the bandwidth to the filter centre frequency. It is therefore no too difficult to add other bandwidth modes as require.


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