THE SPEAKER DISCRIMINATING POWER OF SOUNDS UNDERGOING HISTORICAL CHANGE: A FORMANT-BASED STUDY

This study investigates whether patterns of diachronic sound change within a language variety can predict phonetic variability useful for distinguishing speakers. An analysis of Standard Southern British English (SSBE) monophthongs is undertaken to test whether individuals differ more widely in their realisation of sounds undergoing change than in their realisation of more stable sounds. The vowels /ae, ʊ, uː/, demonstrated by previous research to be changing in SSBE, are compared with the relatively stable /iː, ɑː, ɔː/. Read speech of 50 male speakers of SSBE aged 18-25 from the DyViS database is analysed and compared with earlier results for 20 speakers. First, the data confirm the stability of /iː, ɑː, ɔː/, the fact that /ʊ, uː/ have indeed fronted and that the articulation of /ae/ has become more open. Results from discriminant analysis based on F1 and F2 frequencies show speaker classification rates well above chance. The non-stable vowels all achieved higher levels of discrimination than the stable /ɔː/. However, the highly variable pronunciation of some changing vowels in the case of a few individuals and the ‘special’ status of F1 for /ɑː/ and F2 for /iː/, increasing the rate for those vowels, made the overall picture more complicated.