Tongue-palate contact during bilabials in normal speech

Objective: Previous research using electropalatography (EPG) identified a compensatory articulation called bilabial-lingual double articulations. These double articulations were produced for bilabials by some speakers with cleft palate and involved closure at the lips occurring simultaneously with complete tongue-palate constriction. However, no normative English EPG data exist to confirm the abnormal status of these double articulations. Design: This study reports normative data for EPG contact during bilabial closure. Acoustic and EPG data were recorded for bilabials in different vowel contexts. Participants: Eight normal English-speaking adults. Measures: One measure identified complete tongue-palate constriction, and a second measure calculated percent contact. Results: There were no instances of complete tongue-palate constriction, though some EPG contact occurred in the lateral regions of the palate. The vowel context significantly affected the amount of contact present, with /i/ having the most and /a/ having the least amount of contact. Conclusion: Complete tongue-palate constriction during bilabials of the type found in bilabial-lingual double articulations is not a feature of normal English speech and can therefore be considered an abnormal articulation pattern. Speech-language pathologists who use EPG in their clinical work should be aware that some lateral contact during bilabial closure is normal.