Acoustic and perceptual effects of telephone transmission on vowel quality.

Authors

  • Sophie Lawrence Department of Linguistics, University of Cambridge
  • Francis Nolan Department of Linguistics, University of Cambridge
  • Kirsty McDougall Department of Linguistics, University of Cambridge

DOI:

https://doi.org/10.1558/ijsll.v15i2.161

Keywords:

telephone transmission, acoustic analysis, auditory analysis, formant frequencies, vowel quality, forensic speaker comparison

Abstract

This study investigates acoustic and perceptual effects of telephone transmission on the vowels /i:/, /ae/ and /u:/ in Standard Southern British English. The aim of the study was to determine whether the ‘telephone effect’ described for vowels by Künzel (2001) has an effect on perception as well as on acoustic information. Acoustic measurements confirmed that telephone-transmitted high vowels experience a shift in the frequency of F1. Secondly, a perceptual experiment was carried out in which phoneticians were asked to plot vowels recorded directly and over the telephone on a vowel quadrilateral. Comparing the points plotted for the same tokens recorded directly and over the telephone showed no clear pattern of a perceptual effect of the telephone. However phoneticians’ responses exhibited extensive individual variation, raising a number of questions for future research about the reliability of the auditory analysis of speech. Implications for forensic speaker comparison are discussed.

Author Biographies

  • Sophie Lawrence, Department of Linguistics, University of Cambridge
    Sophie Lawrence has a B.A. (Honours) in linguistics from the University of Cambridge. Her research interests include semantics and pragmatics, particularly politeness theory and cross-cultural communication, Mexican Spanish and forensic phonetics.
  • Francis Nolan, Department of Linguistics, University of Cambridge
    Francis Nolan is Professor of Phonetics in the Department of Linguistics at the University of Cambridge. His research interests range over phonetic theory, intonation, connected speech processes and speaker characteristics. His long-standing involvement in forensic phonetics covers both fundamental research and casework, including technical speaker identification and the use of voice parades. He believes that forensic phonetic practice needs to be underpinned by advances in phonetic theory. He is a founding member of IAFPA.
  • Kirsty McDougall, Department of Linguistics, University of Cambridge
    Kirsty McDougall is a post-doctoral research associate in the Department of Linguistics, University of Cambridge. She has a B.A. in linguistics and a B.Sc. in mathematics and statistics from the University of Melbourne, and an M.Phil. and Ph.D. in linguistics from the University of Cambridge. Her doctoral dissertation is entitled The Role of Formant Dynamics in Determining Speaker Identity. Her research interests include phonetic theory, particularly individual differences in speech production, and forensic phonetics.

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Additional Files

Published

2009-02-15

Issue

Vol. 15 No. 2 (2008)

Section

Articles

License

© Equinox Publishing Ltd.

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How to Cite

Lawrence, S., Nolan, F., & McDougall, K. (2009). Acoustic and perceptual effects of telephone transmission on vowel quality. International Journal of Speech, Language and the Law, 15(2), 161-192. https://doi.org/10.1558/ijsll.v15i2.161