Spectral decrease for audio signals and auditory spectrograms
The spectral decrease is calculated as described in [1]:
where
sk is the spectral value at bin k.
b1 and b2 are the band edges, in bins, over which to calculate the spectral decrease.
[1] Peeters, G. "A Large Set of Audio Features for Sound Description (Similarity and Classification) in the CUIDADO Project." Technical Report; IRCAM: Paris, France, 2004.