Transient detection and preservation in the phase vocoder

In this paper we propose a new method to reduce phase vocoder artifacts during attack transients. In contrast to existing algorithms the new approach does not enforce the time dilation parameter to one during transient segments and works at the level of spectral peaks such that stationary parts of the signal will not be affected by detected transients. For transient detection we propose a new algorithm that is especially adapted for phase vocoder applications because its detection criterion may be interpreted in terms of transient position and and allows us to chose the optimal location for phase reinitialization. The evaluation of the transient detection shows superior performance compared to a previously published algorithm. Attack transients in sound signals transformed with the new algorithm provide very high quality even if strong dilation is applied to polyphonic signals.