Diving Into High-Variability Phonetic Training: Stimuli Type and Learners’ Auditory Selective Attention in Second Language Vowel Training

Abstract

This study investigated the phonetic training performance of 80 first language (L1) Catalan/Spanish advanced second language (L2) English learners in a four-session high-variability phonetic training (HVPT) program and how their training progress interacted with stimuli type (nonwords vs. words) and individual differences in auditory selective attention (ASA). Training included discrimination, identification, and immediate repetition tasks targetting the English vowel contrast /æ/–/ʌ/. L2 vowel perception (accuracy and reaction times) and production (Mahalanobis distances between learners’ productions of /æ/ and /ʌ/) were measured trial-by-trial and across sessions. Results showed a significant performance improvement in discrimination, identification, and repetition irrespective of stimuli type, although learners trained on words generally achieved higher accuracy. ASA predicted performance in both modalities: Stronger attention skills facilitated perceptual accuracy and processing speed and more distinct vowel production in minimal-pair words. Overall, the findings suggest that stimuli type and learners’ attention skills may jointly affect cognitive demands in HVPT and should inform adaptive phonetic training designs.