Multi pitch estimation by using modified IIR Comb Filters

A technique for detecting the pitches of a polyphonic signal of presented. The system utilises modified IIR comb filters, which are generated to ensure that n null (stop band notches) exists at multiples of note frequencies, and that a very flat pass band is present in the remain of the spectrum. Thus, the signal spectrum is not distorted after applying the filters 60 the audio signal, which is the case when using FIR comb filters. The presented approach improves upon an existing multi pitch detection model bared on an FIR comb filter framework