Signal identification for a wide-range sound (piano) using notch and resonator-type comb filters

We propose some methods for the signal identification of 88 tones (from A0 to C8) of a piano sound. A piano sound for a wide range has some difficult problems to estimate the pitch. To manage these problems, first, we divide the sound range into four parts, low, middle 1, middle 2 and high sound parts. Second, we use notch-type comb filters ( H(z) = 1 - z^-N ) for the low part and resonator-type comb filters ( H(z) = 1/(1-z^-N) ) for the middle and high parts to estimate the pitch. We struck on the mean sampling method for accurate realization of the notch and resonator-type comb filters for higher tones. As a result, we could obtain the pitch estimation accuracy of 100% for one tone and 96% for two tones.