Compensating for a bite block in /s/ and /t/ production: palatographic, acoustic, and perceptual data.

Electropalatography was used to monitor linguapalatal contact patterns in /s/ and /t/. Talkers often compensated incompletely for a bite block, both immediately after its insertion (sample B1) and after 10 min of practice (sample B2). Significant differences in the number of sensors contacted were noted between normal and bite-block samples for both /s/ and /t/. Differences in length of constriction in /t/, and the A-P location and width of the groove in /s/ were also noted. The two native English subjects compensated better than three Arabic subjects, perhaps because English /s/ and /t/ are formed more posteriorily and with a smaller contact area than their Arabic counterparts. A significant correlation existed between the area and A-P location of linguapalatal contact. All five subjects formed a groove for /s/ in sample B2, but two often did not produce /t/ with complete constriction. This suggests a groove is critical for /s/, but complete constriction is not critical for /t/. The contact patterns in sample B2 more closely resembled normal speech than those in sample B1 in some instances, while in other instances the reverse was true. The conclusion that subjects sometimes overcompensated in sample B2 was supported by the results of detailed acoustic and perceptual analyses for one subject. Taken together, the results suggest that compensation for a bite block is not instantaneous, and that specific parameter values may be encoded in central phonetic representations.