An evaluation methodology for prosody transformation systems based on chirp signals

Evaluation of prosody transformation systems is an important issue. First, the existing evaluation methodologies focus on parallel evaluation of systems and are not applicable to compare parallel and non-parallel systems. Secondly, these methodologies do not guarantee the independence from other features such as the segmental component. In particular, its influence cannot be neglected during evaluation and introduces a bias in the listening test. To answer these problems, we propose an evaluation methodology that depends only on the melody of the voice and that is applicable in a non-parallel context. Given a melodic contour, we propose to build an audio whistle from a chirp signal model. Experimental results show the efficiency of the proposed method concerning the discrimination of voices using only their melody information. An example of transformation function is also given and the results confirm the applicability of this methodology.