Articulatory strategy in vowel production as a basis for speaker discrimination
This work addresses speaker discrimination for forensic or biometric applications, but it is incremental as it builds on known variability in articulation.
The study investigated whether articulatory strategies in vowel production are sufficiently speaker-specific for speaker discrimination, finding that tongue size was the most discriminatory dimension and anterior tongue shape variation generally outperformed posterior variation.
The way speakers articulate is well known to be variable across individuals while at the same time subject to anatomical and biomechanical constraints. In this study, we ask whether articulatory strategy in vowel production can be sufficiently speaker-specific to form the basis for speaker discrimination. We conducted Generalised Procrustes Analyses of tongue shape data from 40 English speakers from the North West of England, and assessed the speaker-discriminatory potential of orthogonal tongue shape features within the framework of likelihood ratios. Tongue size emerged as the individual dimension with the strongest discriminatory power, while tongue shape variation in the more anterior part of the tongue generally outperformed tongue shape variation in the posterior part. When considered in combination, shape-only information may offer comparable levels of speaker specificity to size-and-shape information, but only when features do not exhibit speaker-level co-variation.