Effects of a simultaneous lip tube and auditory feedback perturbation on the production of the French vowel /u/.

This study investigates the relative weight of somatosensory and auditory feedback in the production of the French vowel /u/ in a simultaneous lip tube and formant shift perturbation. To do so, 20 native Quebec French speakers were recruited. Three experimental conditions involving a lip tube, with each displaying a different auditory condition, were devised. In the first condition, auditory feedback was corrected by canceling the auditory effects of the lip tube using a formant shift. In the second condition, the corrected auditory feedback was replaced with white noise. Finally, access to natural auditory feedback was restored. The results reveal a diversity of compensation strategies depending on the participant. Although some participants rely on auditory feedback to compensate for the lip tube, others compensate before access to natural auditory feedback is restored. It is argued that this could be performed with internal predictions of the auditory feedback using somatosensory feedback, in line, among others, with the dual stream prediction model by Tian and Poppel [J. Cognit. Neurosci. 25(7), 1020--1036 (2013)].