Articulatory strategy in vowel production as a basis for speaker discrimination

TL;DR

This study investigates whether articulatory strategies in vowel production, specifically tongue shape and size, can reliably distinguish individual speakers, highlighting tongue size as a key discriminative feature.

Contribution

The paper demonstrates that tongue size and shape features can be used for speaker discrimination, with tongue size showing the strongest individual discriminatory power.

Findings

Tongue size is the most discriminative feature.

Anterior tongue shape variation outperforms posterior variation.

Shape-only features can match size-and-shape information in speaker discrimination.

Abstract

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.