Acoustic and perceptual analysis of speech adaptation to an artificial palate

The study investigated adaptation to a standard electropalatographic (EPG) practise palate in a group of eight adults (mean age = 24 years). The participants read the phrase "a CVC" over four sampling conditions: prior to inserting the palate, immediately following insertion of the palate, 45 minutes after palate insertion, and 3 hours after insertion of the palate. Perceptual and acoustic analyses were conducted on the initial CV portion of the stimuli. Consonants examined included: /t/, /k/, /s/, and /∫/ followed by the /i/, /a/, and /u/ vowels. Results revealed that individuals within the group were able to adapt their speech articulation to compensate for the presence of the artificial palate. Perceptually, mild consonant imprecision was observed upon insertion of the palate; however, this resolved following 45 minutes to 3 hours of adaptation. Acoustic findings indicated that the palate did not affect segment durations or vowel formant frequencies. However, a significant reduction in M1 for /s/ persisted across the sampling periods. Overall, the results suggest that a period of between 45 minutes and 3 hours of adaptation is generally suitable for participation in EPG studies.