Impact of mobile phone usage on speech spectral features: some preliminary findings

Authors

  • Slobodan T Jovicic Telecommunications Department, School of Electrical Engineering, University of Belgrade, Belgrade, Serbia Laboratory for Forensic Acoustics and Phonetics, Life Activities Advancement Center, Belgrade, Serbia
  • Nikola Jovanović Telecommunications Department, School of Electrical Engineering, University of Belgrade, Belgrade
  • Miško Subotić Laboratory for Forensic Acoustics and Phonetics, Life Activities Advancement Center, Belgrade
  • Đorđe Grozdić Telecommunications Department, School of Electrical Engineering, University of Belgrade Laboratory for Forensic Acoustics and Phonetics, Life Activities Advancement Center, Belgrade

DOI:

https://doi.org/10.1558/ijsll.v22i1.17880

Keywords:

mobile phone usage, speech production, ltass, ltf, vowel formants

Abstract

The manner of using a mobile phone in voice communications can significantly affect the spectral characteristics of the speech signal. This article presents preliminary results of the analysis of the long-term average speech spectrum (LTASS), the long-term formant distribution (LTF) in voiced sounds, and vowel formants F1, F2 and F3 of six speakers in five modes of mobile phone usage. These modes are: normal holding of a mobile phone (NOR), with a bonbon (sweet) in the mouth (BON), with a cigarette between the lips (CIG), with the mobile phone between cheek and shoulder (SHO) and with the hand covering the mobile phone and mouth (HAN). The results show that each mode has an impact on spectral features and that the modes HAN and SHO have the greatest impact. The most striking results are the relative displacement of F1, which can reach 30% (e.g. vowel /a/ in HAN mode for males), formant F2, near 15% (vowel /i/ in SHO mode for males), and formant F3, about 5% (vowel /u/ in CIG mode for females). These findings suggest that forensic practitioners should exercise caution in interpreting formant measurements in speaker identification cases involving mobile phone transmission.

Author Biographies

  • Slobodan T Jovicic, Telecommunications Department, School of Electrical Engineering, University of Belgrade, Belgrade, Serbia Laboratory for Forensic Acoustics and Phonetics, Life Activities Advancement Center, Belgrade, Serbia
    Slobodan T. Jovičić PhD is professor at the Department of Telecommunications, School of Electrical Engineering, University of Belgrade, Serbia. He is a scientific adviser at the Life Activities Advancement Center and a forensic expert at the Serbian Ministry of Justice. He founded the Laboratory for Forensic Acoustics and Phonetics at the Life Activities Advancement Center, Belgrade. His research interests include speech communication, speech technology, speech disorders and forensic science.
  • Nikola Jovanović, Telecommunications Department, School of Electrical Engineering, University of Belgrade, Belgrade
    Nikola Jovanović received his MSc in telecommunications (speech communication) from the School of Electrical Engineering, University of Belgrade, Serbia. He now works as a researcher at the Military Technical Institute, Belgrade. His main research interests lie within the field of speech communication quality enhancement.
  • Miško Subotić, Laboratory for Forensic Acoustics and Phonetics, Life Activities Advancement Center, Belgrade
    Miško Subotić received his PhD in telecommunications (speech communication) from the School of Electrical Engineering, University of Belgrade, Serbia. He is now director of the Life Activities Advancement Center, an innovative center that covers interdisciplinary aspects in speech communication investigation. His research interests include speech production and perception, bioinformatics bases of speech, speech and hearing disorders, and cognitive speech and e-medicine applications.
  • Đorđe Grozdić, Telecommunications Department, School of Electrical Engineering, University of Belgrade Laboratory for Forensic Acoustics and Phonetics, Life Activities Advancement Center, Belgrade
    Đorđe Grozdić received his MSc in telecommunications (speech communication) from the School of Electrical Engineering, University of Belgrade, Serbia. He is now studying for his doctorate at the School of Electrical Engineering and works in the Laboratory for Forensic Acoustics and Phonetics at the Life Activities Advancement Center, Belgrade. His research interests lie within the field of speech perception, recognition and quality enhancement.

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Published

2015-07-08

Issue

Vol. 22 No. 1 (2015)

Section

Articles

License

© Equinox Publishing Ltd.

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How to Cite

Jovicic, S. T., Jovanović, N., Subotić, M., & Grozdić, Đorđe. (2015). Impact of mobile phone usage on speech spectral features: some preliminary findings. International Journal of Speech, Language and the Law, 22(1), 111-126. https://doi.org/10.1558/ijsll.v22i1.17880