Convention Paper
Preserving Reverberation in a Sinusoidally Modeled Pitch Shifter
AES Convention 141 · Paper 9668 · September 2016
Abstract
Many pitch shifting algorithms suffer when the signal contains reverberation. In general, it is possible to preserve the spectral envelope of the original sound, however, an appropriate phase response can only be estimated for minimum phase systems such as vocal formants. This paper presents a pitch shifting algorithm that preserves the reverberant qualities of the original signal by modifying the instantaneous amplitude and frequency trajectories of a sinusoidal model. For each overtone, the sinusoidal trajectories are decomposed into correlated and uncorrelated components and a deviation spectrum is calculated. To synthesize the modified sound, the uncorrelated components are adjusted to preserve the deviation spectrum. The resulting trajectories and sounds are then compared with those of a standard pitch shifter.
