A detailed analysis of a time-domain formant-corrected pitch-shifting algorithm
Robert Bristow-Johnson · Journal of the Audio Engineering Society · 1995
A novel algorithm to perform real-time pitch shifting of quasiperiodic musical tones in such a way as to preserve the apparent spectral envelope has been proposed by Lent in 1989. A functional and analytical comparison is made of this method and most commercial methods of pitch shifting that shift the spectral envelope along with the fundamental frequency. Analytical results show that this method indeed attempts to preserve the spectral envelope similarly to frequency-domain methods that interpolate between discrete spectral lines and resample the interpolated spectrum at the output fundamental and its harmonics