Identification of voices in electronically disguised speech


  • Jessica Clark University of York
  • Paul Foulkes University of York & J P French Associates



vocal disguise, electronic voice changers, speaker identification


We describe an experiment on the effects of electronic vocal disguise on speaker identification. 36 listeners were trained to identify four voices. They then participated in listening tests in which their task was to identify speakers in a set of short stimuli. In the first test the stimuli were natural. For the second test the voices were artificially disguised. The fundamental frequency of the stimuli was modified using Sony SoundForge. As predicted, the rate of correct responses fell for the modified stimuli. The more extreme disguises (±8 semitones) yielded the lowest scores. The majority of listeners performed above chance level in all except the –8 semitone condition. The results showed significant effects for both listener and speaker, in line with previous studies of undisguised and naturally-disguised speaker identification. The variation suggests further research is required to assess the robustness of those forms of electronic disguise used to protect vulnerable witnesses.

Author Biographies

Jessica Clark, University of York

Jessica Clark completed a BA in English Language and Linguistics at the University of York from 2003-6.

Paul Foulkes, University of York & J P French Associates

Paul Foulkes is Reader in Linguistics at the University of York, and course director of the MSc in Forensic Speech Science. He has previously held posts at the Universities of Cambridge, Newcastle and Leeds. He has a BA, MPhil and PhD from the University of Cambridge. As well as forensic phonetics he has research interests in experimental phonetics, phonology, child language acquisition, sociolinguistics and dialectology. His publications include the edited volume Urban Voices, and articles in Language, Journal of Phonetics, Journal of Sociolinguistics, Language and Speech, Journal of Linguistics, Phonology, and the Laboratory Phonology book series. He undertakes forensic casework as a consultant with J P French Associates.



How to Cite

Clark, J., & Foulkes, P. (2008). Identification of voices in electronically disguised speech. International Journal of Speech, Language and the Law, 14(2), 195–221.




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