Camille Fauth

L1-L2 Interference: The case of final devoicing of French voiced fricatives in final position by German learners

This work is dealing with a case of L1-L2 interference in language learning. The Germans learning French as a second language frequently produce unvoiced fricatives in word-final position instead of the expected voiced fricatives. We investigated the production of French fricatives for 16 non-native (8 beginner-and 8 advanced-learners) and 8 native speakers, and designed auditory feedback to help them realize the right voicing feature. The productions of all speakers were categorized either as voiced or unvoiced by experts. The same fricatives were also evaluated by non-experts in a perception experiment targeting VCs. We compare the ratings by experts and non-experts with the feature-based analysis. The ratio of locally unvoiced frames in the consonantal segment and also the ratio between consonantal duration and V1 duration were measured. The acoustic cues of neighboring sounds and pitch-based features play a significant role in the voicing judgment. As expected, we found that beginners face more difficulties to produce voiced fricatives than advanced learners. Also, the production becomes easier for the learners, especially for the beginners, if they practice repetition after a native speaker. We use these findings to design and develop feedback via speech analysis/synthesis technique TD-PSOLA using the learners own voice.

A post-thyroidectomy voice quality study in patients suffering or not from Recurrent laryngeal paralysis

The main object of this study is voice quality after total thyroidectomy (which involves complete removal of the thyroid gland) or isthmolobectomie (which involves removal of the half, right or left, portions of the gland). This often causes degradation of voice quality permanently or temporarily. Voice quality will be studied using aerodynamic cues. From an aerodynamic point of view, oral airflow (Oaf) and maximum phonation time (TMP) were observed. Data from two groups of patients were examined: one group of patients for whom postoperative examination revealed lack of mobility of one of the vocal folds; a second group of patients in whom postoperative examination revealed no perturbation of laryngeal mobility. This is a longitudinal study in which reference values are constituted by the speakers own voice, preoperatively. Preliminary results indicate that removal of the thyroid gland modifies the patients voice even though laryngeal mobility is preserved. All parameters studied underwent changes. However, time has a positive effect on all speakers, since their productions resemble, one month after surgery, the values measured in the preoperative phase.