Successful second language pronunciation learning is linked to domain-general auditory processing rather than music aptitude

Learning a second language (L2) after puberty is well-known to be subject to a great deal of individual variation. Even if two individuals spend the same amount of time practicing a target language, their final outcomes may differ greatly. This could be in part due to the fact that certain individuals are perceptually and cognitively adept at making the most of every practice opportunity (i.e., they possess higher L2 learning aptitude), resulting in more advanced L2 proficiency (Doughty, 2019). Whereas scholars have extensively examined which perceptual-cognitive abilities relate to successful L2 learning, most of the existing literature has been exclusively concerned with lexicogrammar aspects of language learning (Li, 2016). In light of the ongoing discussion regarding the similarities between speech, music and language learning (Tierney, Krizman, & Kraus, 2015), we highlight two overlapping abilities, music aptitude and auditory processing, as a framework of aptitude relevant to successful L2 pronunciation learning. Music aptitude is defined as a set of composite, domain-specific abilities to remember and reproduce music phrases that are no longer physically present, generally measured through standardized tests, and found to relate to L2 pronunciation development to some degree (Slevc & Miyake, 2006). More specifically, scholars have been interested in domain-general sensitivity to more fine-grained properties of acoustic signals (formants, pitch, duration, amplitude), which we refer to here collectively as auditory processing. The ability has been linked to first language (L1) acquisition (e.g., Goswami, 2015), and to L2 acquisition (e.g., Kachlicka, Saito, & Tierney, 2019). To test whether music aptitude and auditory processing abilities explain variation in adult L2 pronunciation learning, we investigated the complex relationship between music aptitude, auditory processing, and biographical profiles of 48 Chinese learners of English in the UK