SpHr_FilterCenterFreqs [ /Type /R /Q=Q /B=minBW /E=[edgesDestWaveName] ] lowestFreq, highestFreq, numBands, destWaveName
Generates center frequencies for a bank of auditory filters. These frequencies are required by subsequent filter bank operations (e.g., SpHr_FilterBankBiquadCoefs and SpHr_FilterBankBiquad).
Parameters
lowestFreq Lowest center frequency generated (Hz).
highestFreq Highest center frequency generated (Hz).
numBands Number of center frequencies generated between lowestFrequency and highestFrequency.
destWaveName Specification for a double precision wave to which center frequencies are written.
Flags
/Type = [type]
type = 1: Glasberg and Moore Parameters, adapted from Malcolm Slaney@Interval. (c) 1998 Interval Research Corporation. Default type, same as when the /Type flag is omitted. See optional flags /Q and /B.
type = 2: logarithmic (exponential) scaling.
type = 3: linearly spaced frequencies.
/Q = [ q ]
Quality factor. If no Q value is passed, the default Glasberg and Moore value of 9.26449 is used.
/B = [ minBW ]
Minimum bandwidth. If no value is passed the default Glasberg and Moore value of 24.7 is used.
/R =[ r ]
/R or /R=1 Rounds each center frequency to its nearest integer value.
/R=0: Same as no /R at all. This is the default.
/R=1: Same as /Z alone.
/E = [ destWaveName ]
Generates coordinate values for displaying frequency-specific results as images (see AppendImage and Image X and Y Coordinates help topic). If destWaveName is omitted, a wave named is 'CFsImageEdges' is made. This wave is double precision and always overwritten.
Example
Function SpHr_FilterCenterFreqs_Example()
variable lowHz = 50
variable highHz = 1500
variable numBands = 50
SpHr_FilterCenterFreqs /Type=2 lowHz, highHz, numBands, CFs
Edit/K=1 root:CFs
End