Voice Imitation : A Phonetic Study of Perceptual Illusions and Acoustic Success

Sammanfattning: This thesis is about voice imitations, more specifically impersonation. Questions are raised about the uniqueness of a person’s voice and speech behaviour and if it is possible to get close to another speaker’s voice and speech. Four main research questions are investigated in different studies. The studies focus mainly on how close the imitation is to the target speaker, and addresses to a lesser degree questions relating to which features are hard to change in a speaker’s voice and speech behaviour. Auditory and acoustic analyses as well as perception tests have been conducted. First, one impersonator and a number of his different voice imitations are investigated in order to get an idea about human voice flexibility. Secondly, another impersonator and one of his target voices are investigated in order to focus on how, and to what extent, the impersonator change his own voice and speech behaviour in order to get close to someone else’s voice and speech. In the third study, imitations made by three different impersonators are investigated in order to get an idea about if they select and try to imitate the same features when imitating the same target voices. Finally, the impact of semantic information on the listener’s acceptance of a voice imitation is tested in voice line-up studies. To succeed, the impersonator has to identify and imitate characteristic features of the target speaker and as a starting point he may think of the target speaker in terms of a caricature and some features will be exaggerated. He may be successful on the whole even if he fails in imitating some features, provided he is successful in imitating other more critical features. The different aspects of the individual voice and speech, pointed out in these studies, are pitch register, voice quality, dialect, prosody and speech style. The impersonator often uses words and phrases related to the target speaker to strengthen the impression of the imitation. The balance between the importance of voice similarity and that of semantic expectation for a successful imitation is discussed.