Musicians are better at learning non-native sound contrasts even in non-tonal languages

Musicians are better at learning non-native sound contrasts even in non-tonal languages Amy Perfors (amy.perfors@adelaide.edu.au) Jia Hoong Ong (jia.h.ong@student.adelaide.edu.au) School of Psychology, University of Adelaide, Australia Abstract of this paper. We perform two main manipulations, com- paring the effectiveness of the same implicit distributional training method on different populations (musicians and non- musicians) as well as different phonemes (tonal and timing- based). We find that musicians show improved phonetic per- ception on all phonemes, and that any effects of training are smaller than these population differences. The implications of these findings for language acquisition and representation more broadly are considered in the discussion. It is very difficult for adults to perceive phonetic contrasts in their non-native language. In this study we explored the effects of phonetic training for different populations of peo- ple (musicians and non-musicians) and with different kinds of phoneme contrast (timing-based, like the Hindi /g/-/k/ con- trast, and pitch-based, like the Mandarin /¯i/-/´i/ tonal contrast). We found that musicians had superior perception for both con- trasts, not just the pitch-based one. For both phonemes, train- ing had little to no effect. We consider the implications of this for first and second language acquisition. Keywords: phonetic learning; music perception; language acquisition; Different phonemes, different populations Tonal vs timing-based phonemes. A phoneme is the small- est unit in a language that forms a meaningful contrast, like the /b/ in bat and the /p/ in pat. Many phonemes are distin- guished from another based on timing. For instance, one of the differences 1 between the English “g” and “k” sounds is the presence of voicing (i.e., the vibration of the vocal cords). English “g” and “k” differ in their voice onset time, or VOT, which refers to the time at which voicing begins and the vocal cords begin to vibrate. For the English “g” sound, voicing is immediate as soon as the tongue leaves the roof of the mouth; for “k”, there is a time delay between the release of the stop closure and the vibration of the vocal cords. Hindi makes a further timing-based distinction that does not exist in English. The Hindi /g/ and /k/ differ according to the presence of pre-voicing, which is the occurrence of voic- ing during the silent interval during which the vocal tract is blocked. Because this distinction does not occur in English, both sound like a “g” to a native English speaker. It is possi- ble to train English speakers to hear this distinction, although they are far below native-speaker proficiency even after the best training. One of the simplest techniques, though not the most common for adults, is implicit distributional train- ing (Hayes-Harb, 2007; Maye & Gerken, 2000; Maye et al., 2008). In this type of training, described in more detail later, participants hear a bimodal distribution of phonemes whose peaks are centered around the two phonemes to be learned. Distributional training has been used to teach adults to distin- guish these Hindi phonemes given as little as 10 minutes of exposure (Maye & Gerken, 2000; Perfors & Dunbar, 2010). Another kind of phoneme occurs in tonal languages like Mandarin, which uses pitch to convey meaning. In such a lan- guage, the meaning of the syllable changes when it is spoken in a different tone. For instance, in Mandarin, ma in the high ¯ ) and the rising Tone 2 ( [m a] ´ ) means mother level Tone 1 ( [m a] Introduction Second language learning is a difficult task for a variety of reasons. Adults have difficulty with many aspects of lan- guage acquisition, including language processing (Clahsen & Felser, 2006) and certain aspects of syntax (e.g., Bird- song, 2006), but limitations in phonetic perception relative to infants and young children are especially strong and well- documented (e.g., Werker & Lalonde, 1988; Kuhl, 2004; Maye, Weiss, & Aslin, 2008). Phonological deficits can be found not just in perception, but in production and processing as well (e.g., Flege, 1995; Sebasti´an-Gall´es & Soto-Faraco, 1999). Such deficits are sometimes thought to have cascading effects onto other aspects of language (Perani, 2005; Werker & Yeung, 2005; Perfors & Dunbar, 2010). One striking aspect of adults’ poor phonetic perception is that it is quite difficult to overcome it through training. There are various training regimes for teaching adults to learn a phonetic contrast that does not exist in their native language. Some rely on implicit learning of the phonemic categories based on distributional information (Maye & Gerken, 2001, 2002; Shea & Curtin, 2005; Hayes-Harb, 2007), while in oth- ers some form of feedback is given (e.g., Jamieson & Mo- rosan, 1989; McCandliss, Fiez, Protopapas, Conway, & Mc- Clelland, 2002; Wang, Jongman, & Soreno, 2003; Golestani & Zatorre, 2004; Wayland & Li, 2008; Bradlow, 2008). These training regimes have rarely been compared directly, and are often used for different kinds of phonemes and with different goals. It is therefore still unclear precisely to what extent different kinds of training are effective and why. Given the importance of phonetic perception, understand- ing why phonetic training works (to the extent it does) and how it can be improved (to the extent it doesn’t) is a mat- ter of some importance. One of the ways to explore this is by investigating the effectiveness of training on different kinds of phonemes as well as in different populations of peo- ple. Expanding this exploration is one of the central goals 1 The other difference between these two phonemes is aspiration, which refers to the presence of a puff of air after making a sound ( /g/ is not aspirated but /k/ is). We do not considering aspiration here.