Vibrato: detection, estimation, extraction, modification

S. Rossignol; P. Depalle; J. Soumagne; X. Rodet; J.-L. Collette
DAFx-1999 - Trondheim
This paper deals with vibrato detection, vibrato extraction on f 0 trajectory, and vibrato parameter estimation and modification. Vibrato detection and extraction are aimed at being a first step for note segmentation of singing voice signals. The aim is also to characterize sounds with the descriptor: "presence of vibrato" or "absence of vibrato". Changing vibrato parameters, that is to say its magnitude and its frequency, is also one of the possible musical applications. It is firstly required to detect the presence of vibrato. In order to do that, several approaches are possible: we can analyse directly the sound signal or its f 0 trajectory. For each approach, several techniques exist: some of them are described here: the "spectrum modelling" method, the "spectral envelopes distortion" method, the "AR prediction" method, the "analytic signal" method and the "minima - maxima detection" method. Their performance are compared. Secondly, the parameterization is completed: if there is vibrato, the parameters of the vibrato, that is to say its frequency and its magnitude, are given. Thirdly, the vibrato is extracted on f 0 trajectory to obtain a no-vibrato melodic evolution. This "flat" fundamental frequency is useful for segmentation of musical excerpts into notes, but can also be used for sound modification or processing.