Vowel context, rate and loudness effects on linguopalatal contact patterns in Hindi retroflex /t/

A 96-channel electropalatograph was used to monitor linguopalatal contact patterns during normal, fast and loud productions of retroflex /t/ in the nonsense words /bitib/, /butub// and /batab/ spoken in a carrier sentence by a native speaker of Hindi. A complete constriction was observed in all three vowel contexts and in all three speech conditions, suggesting that a tongue-palate constriction is a critical articulatory parameter for /t/. The contact pattern during maximal constriction in each token was examined for the anterior-posterior (A-P) location of the contact, its length in the A-P dimension, and its extent (as measured by number of contacted electrodes). The location of the constriction was more posterior in the context of /a/ than /u/ than /i/, indicating a strong coarticulatory effect of vowel context on /t/. This coarticulatory shift in the A-P location of /t/ constriction suggests that the degree of retroflexion decreased systematically from /a/ to /u/ to /i/ context. The A-P location of the /t/ constriction was also more posterior in the fast than normal or loud speech. However, other aspects of the contact pattern suggest that this shift reflects locational undershoot. The hypothesis that the extent of linguopalatal contact and the A-P length of /t/ constriction might increase in loud and fast speech compared with that in normal speech was only partially supported for loud speech, and remained largely unsupported for fast speech.