How do you calculate spectral entropy?
To compute the instantaneous spectral entropy given a time-frequency power spectrogram S(t,f), the probability distribution at time t is: P ( t , m ) = S ( t , m ) ∑ f S ( t , f ) . Then the spectral entropy at time t is: H ( t ) = − ∑ m = 1 N P ( t , m ) log 2 P ( t , m ) .
What is a flat spectrum?
Spectral flatness or tonality coefficient, also known as Wiener entropy, is a measure used in digital signal processing to characterize an audio spectrum. Spectral flatness is typically measured in decibels, and provides a way to quantify how much a sound resembles a pure tone, as opposed to being noise-like.