Patent ID: 8311811

Claim:
A method of detecting a pitch in input voice signals, the method comprising: performing a Fourier transform on the input voice signals after performing a pre-processing on the input voice signals; performing an interpolation on the transformed voice signals; calculating a normalized local center of gravity (NLCG) on a spectrum of the interpolated voice signals; calculating a spectral auto-correlation using the calculated NLCG; determining a voicing region based on the calculated spectral auto-correlation; calculating a cumulated sum of the calculated NLCG; calculating a subharmonic-to-harmonic ratio (SHR) from the spectrum based on the calculated cumulated sum; and extracting a pitch, using a processor, based on the calculated SHR corresponding to the voicing region, wherein the NLCG is calculated by the equation below, · cA ⁡ ( f i ) = 1 U ⁢ ∑ j = 1 j = U ⁢ ⁢ iA ⁡ ( f i - U / 2 + j ) ∑ j = 1 j = U ⁢ ⁢ A ⁡ ( f i - U / 2 + j ) - 0.5 with U being a local region and A(f) being a spectrum amplitude.