Dworkin, James Paul

The purpose of this investigation was to determine the relationships among frontal lisping, protrusive lingual force, and lingual diadochokinetic rates when subjects are grouped according to severity of lisping. Results revealed that when compared to normal speaking counterparts: (1) lispers in each severity subgroup exhibited significantly weaker protrusive lingual forces and that the significance of such differences increased with the severity of lisping; and (2) all but the moderately severe lispers displayed significantly slower lingual diadochokinetic rates. These findings suggest that clustering lispers into homogeneous severity subgroups before examining the relationships between their misarticulations and the lingual factors studied may offer important information regarding the diagnosis, treatment, and prognosis of their articulatory problems.

Tongue force, rate of syllable repetition, and judgments of articulatory defectiveness were measures obtained on 19 dysarthric adults with amyotrophic lateral sclerosis and on 125 normal adults. Anterior and lateral tongue forces were measured by means of a pressure transducer clasped between the teeth; the tongue forces were recorded on a pen-writing ECG apparatus. Audio-recorded syllable repetitions of /p/, /t/, and /k/ also were transcribed on ECG paper and counted. Three listeners rated articulatory precision on a 7-point scale of severity. The normal males had significantly higher tongue forces than normal females; normal subjects had significantly higher tongue forces than dysarthric patients; and anterior tongue forces were significantly greater than lateral in normal and dysarthric patients. There was a high negative correlation between tongue force and severity of articulatory defect. Syllable repetitions were significantly slower in the dysarthric patients than in the normal patients, and a high negative correlation was obtained between syllabic rate and severity of articulatory defect.