Labial-Lingual Double Articulations in Speakers with Cleft Palate

Abstract

Labial-lingual double articulations (LLDAs) are speech errors involving simultaneous valving at the lips and in the linguapalatal region. This study investigates the frequency of LLDAs occurring for /p/, /b/, and /m/ targets and describes the linguapalatal contact patterns involved in these abnormal articulations. A retrospective study involving analysis of articulatory data from all speakers with cleft palate recorded at a research center over a 10-year period. Twenty-seven speakers aged 5 to 62 years (median 11 years) with compensatory speech errors associated with repaired cleft palate. The lingual component of LLDAs was identified using electropalatography (EPG). EPG data were recorded simultaneously with acoustic data. Fifteen bilabial targets (/p/, /b/, /m/) per participant were analyzed. LLDAs were identified in cases where complete linguapalatal constriction (as observed from EPG data) occurred throughout the closure phase of bilabial targets. The labial component of LLDAs was identified from clinical observations of the speakers made during productions of bilabial targets. Three speakers (11%) frequently produced LLDAs for bilabial targets. The configuration of tongue-palate contacts involved in the lingual component of the LLDAs differed in each of the three speakers: one speaker had velar constriction, another had alveolar constriction, and the third had simultaneous alveolar-velar constriction. LLDAs did not similarly affect bilabial targets in the three speakers. One speaker produced LLDAs for /p/ and /b/ targets only. Another produced LLDAs for all /m/ targets but inconsistently for /p/ and /b/ targets. The third speaker produced LLDAs for all /b/ targets but inconsistently for /p/ and /m/ targets. LLDAs occurred in a minority of speakers investigated. Nevertheless, it is argued that it is important to identify LLDAs for clinical decision making and for research purposes. The results from this study add to current knowledge about abnormal articulations in cleft palate speech, but further research is needed into the precise timing of lip and tongue-palate closures and into the airflow and acoustic characteristics of LLDAs.