Vowel Variation

This theme investigates the influence of speech styles—elicited versus spontaneous—along with contextual assimilation, speech duration, and speaker sex, on vowel production variability and dispersion. Research is particularly focused on endangered languages and spontaneous speech contexts, where reduced clarity and increased variability present challenges for phonetic documentation and analysis. Understanding these effects is crucial for accurately capturing vowel systems in naturalistic language use and for developing methodologies that allow reliable phonetic analysis despite stylistic variation.

This research area examines temporal stability and systematic variability of vowel production within individual speakers over hours and days, as well as cross-dialectal and cross-linguistic comparisons of vowel realizations focusing on acoustic dimensions such as formant frequencies and duration. Studying intra- and inter-speaker variability is important for understanding speech motor control, phonetic category stability, and language variation, and has implications for speech technology, phonetic normalization, and intelligibility among different speaker populations.

This theme interrogates the relationship between articulatory and acoustic correlates of vowel features, notably vowel height and phonemic length, exploring whether duration is independently controlled or reflects articulatory constraints like jaw movement. It also addresses how vowel quality and quantity distinctions are acoustically instantiated and the extent to which these phonetic parameters vary systematically or overlap, affecting phonological contrast maintenance. Insights are drawn from diverse languages including English, Norwegian, and Southern British English, highlighting cross-linguistic factors shaping vowel duration and quality.