The Effects of Forensically Relevant Face Coverings on the Acoustic Properties of Fricatives

  • Julie Saigusa
Keywords: intraspeaker variation, sociophonetics, UK English, forensic linguistics


This forensically motivated study investigates the effects of a motorcycle helmet, balaclava, and plastic mask on the acoustics of three English non-sibilant fricatives, /f/, /θ/, and /v/ in two individuals. It examines variation within the individual as an effect of the physical environment. Two speakers recorded a list of minimal pairs in each of the three guises and with no face covering. The results showed that facewear significantly affected fricative intensity and the four spectral moments: centre of gravity, standard deviation, skewness, and kurtosis. The acoustic changes caused by facewear have implications for judging the reliability of earwitnesses’ content recall and voice identification as well as forensic speech scientists’ examination of content and speaker identity in disputed recordings.


Bennett, Joe. 2012. ‘And what comes out may be a kind of screeching’: The stylisation of chavspeak in contemporary Britain. Journal of Sociolinguistics 16(1):5–27.
Blevins, Juliette. 2004. Evolutionary Phonology: The Emergence of Sound Patterns. Cambridge: Cambridge University Press.
Boersma, Paul, and David Weenink. 2009. Praat: Doing phonetics by computer [Computer programme, Version 6.0.09). Accessed,
Broeders, A. P. A. 2013. Earwitness identification: Common ground, disputed territory and uncharted areas. International Journal of Speech Language and the Law 3(1):3–13.
chavspotting. 2004. chav [Urban Dictionary entry]. Accessed 29 March 2016,
Clark, Lynn, and Graeme Trousdale. 2009. Exploring the role of token frequency in phonological change: Evidence from th-fronting in east-central Scotland. English Language and Linguistics 13(1):33–55.
Davies, Mark. 2004. Byu-bnc [Corpus based on the British National Corpus from Oxford University Press]. Accessed,
Elvira-Garcia, Wendy. 2014. Zero crossings and spectral moments [Praat script v.1.3.]. Accessed,
Fecher, Natalie. 2014. Effects of forensically-relevant facial concealment on acoustic and perceptual properties of consonants. Doctoral dissertation, University of York.
Flege, James Emil, Samuel G. Fletcher, and Abdullah Homiedan. 1988. Compensating for a bite block in /s/ and /t/ production: Palatographic, acoustic, and perceptual data. The Journal of the Acoustical Society of America 83(1):212–228.
Fraser, Helen. 2014. Transcription of indistinct forensic recordings: Problems and solutions from the perspective of phonetic science. Language and Law/Linguagem e Direito 1(2):5–21.
Fraser, Helen, Bruce Stevenson, and Tony Marks. 2011. Interpretation of a crisis call: The persistence of primed perception of speech. The International Journal of Speech Language and the Law 18 (2):261–292.
Garnier, Maeva, Nathalie Henrich, and Daniele Dubois. 2010. Influence of sound immersion and communicative interaction on the Lombard effect. Journal of Speech, Language, and Hearing Research 53(3):588–608.
Gold, Erica, and Peter French. 2011. International practices in forensic speaker comparison. International Journal of Speech, Language and the Law 18(2):293–307.
Hardcastle, William. J., John Laver, and Fiona E. Gibbon. 2010. The Handbook of Phonetic Sciences. Chichester: John Wiley & Sons.
Laub, Cindy E., Lindsey E. Wylie, and Brian H. Bornstein. 2013. Can the courts tell an ear from an eye: Legal approaches to voice identification evidence. Law and Psychology Review 37:119–249.
Lennes, Mietta. 2002. Save labeled intervals to wav sound files [Praat script]. Accessed 29 March 2016, cdicanio/scripts.html
Levon, Erez, and Sue Fox. 2014. Social salience and the sociolinguistic monitor: A case study of ing and th-fronting in Britain. Journal of English Linguistics 42(3):185–217.
Lindblom, Björn, James Lubker, and Thomas Gay. 1979. Formant frequencies of some fixed-mandible vowels and a model of speech motor programming by predictive simulation. Journal of Phonetics 7(2):147–161.
Ling, Jonathan, and Allison Coombe. 2005. Age effects in earwitness recall of a novel conversation 1. Perceptual and Motor Skills 100(3):774–776.
Llamas, Carmen, Philip Harrison, Damien Donnelly, and Dominic Watt. 2008. Effects of different types of face coverings on speech acoustics and intelligibility. York Papers in Linguistics (Series 2) 9:80–104.
Martin, A., Howell, K., & Lower, M. 1976. Hearing Protection and Communication in Noise (Vol. 2). London: Academic Press London.
Martinez, Lauren, and Barney Lerten. 2016. Ski-masked gunman holds up NE Bend bank, gets away. Accessed 29 March 2016,
McFarland, David H., and Shari R. Baum. 1995. Incomplete compensation to articulatory perturbation. The Journal of the Acoustical Society of America 97(3):1865–1873.
Miller, George A., and Patricia E. Nicely. 1955. An analysis of perceptual confusions among some English consonants. The Journal of the Acoustical Society of America 27(2):338–352.
Niedzielski, Nancy. 1999. The effect of social information on the perception of sociolinguistic variables. Journal of Language and Social Psychology 18(1):62–85.
Noy, D. 2003. Evaluation of transmission loss induced by stretched fabric treatments.
Ohala, John J., and Haruko Kawasaki. 1984. Prosodic phonology and phonetics. Phonology 1:113–127.
Podlubny, Ryan G., Jen Hay, and Megan McAuliffe. 2016. Car-talk: How physical environment influences speech production and perception. In Proceedings of the 15th Conference on Laboratory Phonology.
R Core Team. 2015. R: A language and environment for statistical computing [Computer software manual]. Accessed,
Radonovich Jr., Lewis J., Robert Yanke, Jing Cheng, and Bradley Bender. 2009. Diminished speech intelligibility associated with certain types of respirators worn by healthcare workers. Journal of Occupational and Environmental Hygiene 7(1):63–70.
Saigusa, Julie. 2016. Jane lynch and /s/: The effect of addressee sexuality on fricative realization. Lifespans and Styles 2(1):10–16.
Schleef, Erik, and Michael Ramsammy. 2013. Labiodental fronting of /θ/ in London and Edinburgh: A cross-dialectal study. English Language and Linguistics 17(01):25–54.
Sommer, Henry C. 1976. Speech communication capability and hearing protection of USAF inflight headgear devices (Technical Report, DTIC).
Stevens, Kenneth. N. 1989. On the quantal nature of speech. Journal of Phonetics 17:3–45.
Tabain, Marija. 1998. Non-sibilant fricatives in English: Spectral information above 10 kHz. Phonetica 55(3):107–130.
Tabain, Marija, and Catherine Watson. 1996. Classification of fricatives. In Proceedings of the Sixth Australian International Conference on Speech Science and Technology, ed. P. McCormack and A. Russell, 623–628. Canberra: Australian Speech Science and Technology Association.
Thomas, Erik R. 2002. Sociophonetic applications of speech perception experiments. American Speech 77(2):115–147.
Tufts, Jennifer B., and Tom Frank. 2003. Speech production in noise with and without hearing protection. The Journal of the Acoustical Society of America 114(2):1069–1080.
Watt, Dominic 2013. Research methods in speech acoustics. In The Bloomsbury Companion to Phonetics, ed. M. J. Jones and R.A. Knight, 79–97. London: Bloomsbury.
Wells, Gary L., and Elizabeth A. Olson. 2003. Eyewitness testimony. Annual Review of Psychology 54(1):277–295.
Wickham, Hadley. 2009. ggplot2: Elegant graphics for data analysis. Springer-Verlag New York. Accessed,
Wittum, Kelsi J., Lawrence Feth, and Evelyn Hoglund. 2013. The effects of surgical masks on speech perception in noise. In Proceedings of Meetings on Acoustics 19, 060125.
Yarmey, Daniel A. 2007. Earwitness descriptions and speaker identification. International Journal of Speech Language and the Law 8(1):113–122.
How to Cite
Saigusa, J. “The Effects of Forensically Relevant Face Coverings on the Acoustic Properties of Fricatives”. Lifespans and Styles, Vol. 3, no. 2, June 2017, pp. 40-52, doi:10.2218/ls.v3i2.2017.1866.