Is Tongue Strength an Important Influence on Rate of Articulation in Diadochokinetic and Reading Tasks?

Abstract

Purpose The purpose of this study was to assess the relationship between tongue strength and rate of articulation in 2 speech tasks, diadochokinetic rates and reading aloud, in healthy men and women between 20 and 78 years of age. Method Diadochokinetic rates were measured for the syllables /pʌ/, /tʌ/, /kʌ/, and /pʌtəkə/, and articulation rates were calculated for a reading of the Rainbow Passage for 57 adult volunteers. The Iowa Oral Performance Instrument (LLC Northwest) was used to obtain maximum tongue pressure, tongue pressure exerted during production of /tʌ/, and tongue endurance. Correlation analyses were performed to determine the relation among articulation rate and tongue pressure and endurance measures. Results Maximum tongue pressure, the pressure used to produce /tʌ/, the proportion of maximum pressure used to produce /tʌ/, and tongue endurance were poor predictors of diadochokinetic rates and articulation rate in reading for healthy speakers. Discussion Focus must remain on factors beyond strength, such as movement precision and coordination, to improve researchers' understanding of normal and disordered speech production in adults.