Introducing Roughness in Individuality Transformation through Jitter Modeling and Modification
Ashish Kumar Verma, Arun Kumar · 2006
Individuality transformation is a process to modify the speech signal in a person's voice so that it sounds as if it is spoken by another person. In most individuality transformation methods, pitch transformation is performed through a simple scaling considering the global pitch characteristics of the source and target speakers without considering the short-term pitch variation or jitter. We present a novel method to model and modify jitter in the speech signal to introduce a handle on roughness in the process of individuality transformation. The proposed method is based upon computing the average intensity in a band around the fundamental frequency in the spectrum of a speaker's mean normalized pitch contour. The validity of the proposed method to model jitter has been established by subjective tests for perceived roughness in the speaker's voice. It is also shown that modification of jitter by the proposed method results in an improved subjective rating for individuality transformation.