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Implemented Model for Tonality

The tonality of a frequency bin tex2html_wrap_inline982 is estimated by looking at the predictability of the phase and magnitude of that Fourier coefficient. The predictors are defined as follows:



The phase is thus linearly extrapolated from two former time instances, and magnitude is simply assumed to be the same as last. This gives no prediction error for one stationary sine within the frequency band. The tonality is then estimated from the maximum prediction error of the last two phase values and the last magnitude:


where tex2html_wrap_inline1020 and tex2html_wrap_inline1022 . This model gives a weighted average t of about 0.9 for highly tonal sting music, and 0.3 for white noise. Of course the parameters in the masking threshold (section 3.2.5) estimation are adapted to these (non-ideal) values.

Bosse Lincoln
Sat Mar 7 16:27:43 PST 1998