Innovation in Language Learning

The present work is a pilot study aiming at describing the contribution of ultrasound tongue imagining in second language (L2) vowel production training.

Ultrasound (US) has been successfully used as a visual biofeedback tool in L2 segment learning such as for the French /y-u/ contrast by Japanese learners (Pillot-Loiseau et al., 2013). Indeed, if learners are able to monitor directly the articulators, then they can be aware of the adjustments needed to reach the L2 articulatory goal (Wilson & Gick, 2006). The English vowel contrast /ɑ/-/ʌ/ (e.g., cop-cup) is really difficult to perceive (Escudero et al., 2014) and produce by Italian learners (Flege et al., 2009). It is cued by differences in tongue backness and height that cannot be easily detected without direct visual information. Therefore, US visual training has been performed on L2 /ɑ/-/ʌ/.

Three Salento Italian monolingual adults, i.e., experimental subjects (ES), received a 1-hour training session while three control subjects (CS) did not. First, the phonetic differences within the target contrast and between the contrast and the closest native vowels, i.e., /a/-/o/, were explained. Second, L2 /ɑ/-/ʌ/ and /i/-/u/ (control) were presented by means of US audio/videos (previously recorded by three English native speakers) where the sagittal view of the tongue contours of isolated vowels (10 times each at least) and CVC pseudo-words (3 per vowel repeated at least 10 times each) were visible. Finally, according to their proficiencies/preferences, the subjects practiced with the US probe under their chin, also producing L1 control /a-o/ (3 CVC x 10 times), in order to have (i) a visual feedback of the position and movements of their tongue during L1/L2 vowel production and (ii) corrective instructions by the first two authors of the present study.

Both the ES and the CS were recorded before and after the training session. Acoustic analysis of their productions (F1, tongue height; F2, tongue backness) revealed an improvement between pre and post-training for the ES only both in terms of F1 and F2 when compared with English native productions. Thus, ultrasound training has a beneficial effect on the pronunciation of L2 /ɑ/-/ʌ/ by Italian learners.