Poster D56, Wednesday, August 21, 2019, 5:15 – 7:00 pm, Restaurant Hall
Optimization in non-native speech sound production
Clara Martin1,2, Kirk Goddard1, Maria Koutsogiannaki1, Natalia Kartushina3;1Basque Center on Cognition, Brain and Language (BCBL), 2Ikerbasque, 3University of Oslo
Several studies on speech motor control have shown that online alteration of auditory feedback often leads to motor adjustments in speaker’s phoneme production. For example, when a speaker produces /pep/ but hears through her headphones a more open vowel, such as /pap/ (via an online perturbation of her own voice), the speaker tends to adjust her production towards a more closed vowel, as in /pip/ (i.e., in the opposite direction to the alteration). This is a manifestation of a speaker unconsciously adjusting their speech sound production via altered auditory feedback. The present study investigated whether this type of production training can be used to improve non-native speech sound production, and, if so, whether production improvements transfer to perception. Thus, unlike traditional trainings, the current study attempted to influence and improve production of a non-native sound (i.e., the articulatory target) without going through the classical perception-to-production transfer. We used the online feedback alteration device (FAD) to lead native Spanish speakers (N=11) with low English proficiency to produce the English vowel /ɪ/ (frequently assimilated to the Spanish /i/). During three one-hour FAD sessions (on three consecutive days), participants had to repeatedly produce the Spanish pseudoword /pip/, while their auditory feedback was altered online to induce articulatory adaptation towards /pɪp/. Participants were tested on a series of perception and production tasks, before and after the FAD sessions, and one week later. At each testing session, we measured their production (picture naming), their discrimination (AXB task), and their categorization (3-alternative forced-choice task) of the target English vowel /ɪ/ as well as the closest vowels /i/ and /e/. A control group (N=10) performed the exact same sequence of tasks and sessions but their auditory feedback was never altered. Over the three-day training with FAD, we found that participants unconsciously shifted their production towards the target English vowel /ɪ/. By comparing pre- and post-tests, we observed that participants improved their production of the target sound during picture naming, and this improved production generalized to other words. In addition, we found that training improved their ability to categorize the English vowel /ɪ/ when presented with the vowels /i/ and /e/. No significant training effect was observed on discrimination, due to a ceiling effect already at pre-test. Importantly, improvements in speech sound production and categorization remained one week later. The control group did not significantly improve in any of the tasks, showing that the effect was due to feedback alteration and not task repetition. These results have important implications for theories on motor control: Compensation to feedback alteration takes place with non-native speech sounds, can be long-lasting, and transfers to perception. Plus, this study opens interesting avenues for foreign language learning: By showing that foreign accent in phoneme production can be minimized, we propose that FAD can be used as a training tool to efficiently drive second language speakers towards native-like pronunciation. This is essential given that foreign accent is known to be associated with negative judgments from native listeners (lack of credibility and intelligence).
Themes: Language Production, Speech Motor Control
Method: Behavioral