streaming mode | Spectral category


  • spectrum (vector_real) - the input audio spectrum (must have more than one elements)


  • rollOff (real) - the roll-off frequency [Hz]


  • cutoff (real ∈ (0, 1), default = 0.85) :

    the ratio of total energy to attain before yielding the roll-off frequency

  • sampleRate (real ∈ (0, ∞), default = 44100) :

    the sampling rate of the audio signal (used to normalize rollOff) [Hz]


This algorithm computes the roll-off frequency of a spectrum. The roll-off frequency is defined as the frequency under which some percentage (cutoff) of the total energy of the spectrum is contained. The roll-off frequency can be used to distinguish between harmonic (below roll-off) and noisy sounds (above roll-off).

An exception is thrown if the input audio spectrum is smaller than 2.


[1] G. Peeters, “A large set of audio features for sound description (similarity and classification) in the CUIDADO project,” CUIDADO I.S.T. Project Report, 2004

Source code

See also

RollOff (standard)