Impact of Voice Onset Time on Phoneme Perception and Implications for a Language-Agnostic Hearing Assessment.

Purpose: The aim of this study was to evaluate the effect of native language on phoneme perception in normal-hearing (NH) adults representing the three most commonly spoken languages in the United States (English, Spanish, and Mandarin Chinese).

Method: A prospective cross-sectional study was performed at a tertiary care institution. Ninety-five NH young adults completed Experiment 1: 36 native English, 32 native Mandarin, and 27 native Spanish speakers, with an average age of 21.5 years, recruited from a university population. A subset of 30 NH participants drawn from the Experiment 1 cohort (10 per language group) completed Experiment 2. In Experiment 1, a two-alternative forced-choice (2AFC) same-different paradigm was developed using paired stimuli drawn from an 11-step continuum spanning English /d/-/t/ voice onset time (VOT). Pairs were categorized as subtle, intermediate, or pronounced based on degree of VOT contrast. Experiment 2 utilized a 3AFC odd-one-out paradigm with 16 tasks, with an expanded stimulus library. The stimuli were consonant-vowel (CV) and VCV phrases that were inclusive of voicing contrast but also place, manner, and vowel contrasts.

Results: Overall performance in Experiment 1 did not differ significantly across language groups (χ² = 4.81, p = .090). However, when stratified by degree of VOT contrast, a significant group effect emerged for intermediate VOT pairs (χ² = 7.59, p = .023), driven by differences between Mandarin and Spanish speakers (χ² = 7.59, p = .0059, Bonferroni corrected). No significant differences were observed between English speakers and either of the other groups. In Experiment 2, all three language groups achieved 100% accuracy across phoneme pairs spanning multiple contrast types, with no language-related differences detected.

Conclusions: While native language affects discrimination of intermediate VOT contrasts in NH adults, performance converges when using a broader set of stimuli. These results provide preliminary support for discrimination-based approaches to speech perception assessment and highlight the importance of stimulus selection and task design in minimizing language-related bias. Further studies are required to evaluate sensitivity and clinical applicability in more challenging listening environments and with hard of hearing populations.

Supplemental material: https://doi.org/10.23641/asha.33470986.