specfilt — Filters each channel of an input spectrum.


Filters each channel of an input spectrum.


wsig specfilt wsigin, ifhtim


ifhtim -- half-time constant.


wsigin -- the input spectrum.

Filters each channel of an input spectrum. At each new frame of wsigin, each magnitude value is injected into a 1st-order lowpass recursive filter, whose half-time constant has been initially set by sampling the ftable ifhtim across the (logarithmic) frequency space of the input spectrum. This unit effectively applies a persistence factor to the data occurring in each spectral channel, and is useful for simulating the energy integration that occurs during auditory perception. It may also be used as a time-attenuated running histogram of the spectral distribution.


  wsig2    specdiff    wsig1         ; sense onsets
  wsig3    specfilt    wsig2, 2      ; absorb slowly
           specdisp    wsig2, 0.1    ; & display both spectra
           specdisp    wsig3, 0.1

See Also

specaddm, specdiff, spechist, specscal