The role of glottal source parameters for high-quality transformation of perceptual age

The intuitive control of voice transformation (e.g., age/sex, emotions) is useful to extend the expressive repertoire of a voice. This paper explores the role of glottal source parameters for the control of voice transformation. First, the SVLN speech synthesizer (Separation of the Vocal-tract with the Liljencrants-fant model plus Noise) is used to represent the glottal source parameters (and thus, voice quality) during speech analysis and synthesis. Then, a simple statistical method is presented to control speech parameters during voice transformation: a GMM is used to model the speech parameters of a voice, and regressions are then used to adapt the GMMs statistics (mean and variance) to a control parameter (e.g., age/sex, emotions). A subjective experiment conducted on the control of perceptual age proves the importance of the glottal source parameters for the control of voice transformation, and shows the efficiency of the statistical model to control voice parameters while preserving a high-quality of the voice transformation.