Manner-specific tongue shape differences in the production of Kannada coronal consonants

Abstract

The production of consonants of the same place but different manner of articulation can involve certain adjustments in the posture of the tongue shape. This can be due to requirements for specific gestures (e.g., lowering the tongue sides for laterals) or constraints on coordination of different gestures (e.g., the tongue-palate constriction and the velum lowering for nasals). This study used ultrasound imaging to examine sagittal tongue shape differences in the production of Kannada (Dravidian) laterals, nasals, and stops of two places of articulation—alveolar/dental and retroflex. Words with these consonants (as geminates) were produced multiple times by five female and five male native speakers of Kannada. The analysis of tongue shapes revealed a lower tongue body/blade for laterals than stops, but only in retroflexes. The opposite was observed for /l/ vs. /t/, likely reflecting the alveolar vs. dental constriction differences. The nasals were produced with a significantly more advanced tongue body than the corresponding laterals and stops. The tongue fronting for nasals can serve to accommodate the velum lowering as part of these consonants' gestural coordination. The magnitude of this effect is further modulated by the consonant’s degree of articulatory resistance, which is greater for retroflexes than alveolars/dentals.