We conducted a comparative study of a voice produced by a professional impersonator imitating a target speaker to explore the acoustical characteristics that the impersonator changes from his natural voice to imitate a target voice. Comparison of the pitch frequency of the target and imitated voices showed that the mean and dynamics of the pitch frequency of the imitated voice are changed so that they become closer to those of the target voice. The spectra of vowels uttered by the speakers are also similar in their shape and formant frequencies. In the imitated voice, the formant frequencies shift by up to 68% from those of the impersonator's natural voice. Moreover, the differences between the amplitudes of the first and second harmonics (H1-H2), a measure of the glottal source characteristics, of the target and imitated voices are small. These results clearly demonstrate that the impersonator controls vocal tract acoustic characteristics as well as those of the glottal source and pitch frequency to imitate the target voice.
Bibliographic reference. Kitamura, Tatsuya (2008): "Acoustic analysis of imitated voice produced by a professional impersonator", In INTERSPEECH-2008, 813-816.