Overcoming stress deafness: the interplay of musical acuity and L2 proficiency in Czech learners’ perception of English stress

Listeners whose first language has fixed stress often struggle to perceive word stress in a second language (L2), a phenomenon known as "stress deafness." This study investigates how L2 proficiency and musical perception skills jointly influence Czech learners' perception of English lexical stress. Fifty-four Czech adults, representing a wide range of English proficiency (measured by LexTALE) and musical perception skills (measured by PROMS-S), completed an AXB discrimination task with English pseudowords differing segmentally and in stress placement. Mixed-effects logistic regression revealed main effects of both L2 vocabulary size and musical perception ability, as well as their interaction: highly accurate stress discrimination required high scores for both measures. Unlike much previous research, which often found no effect of L2 proficiency, the present study did find one, possibly because the effect was disentangled from individual differences in auditory acuity by including musical aptitude measures. Analysis of the musical subtests showed that temporal (tempo, rhythm) and dynamic (beat) perception predicted stress discrimination, whereas tonal and spectral skills did not. These results demonstrate that temporal auditory acuity enhances the perception of L2 stress, particularly when combined with robust L2 lexical knowledge, highlighting the interplay of linguistic and domain-general auditory factors in L2 prosodic learning.