The relationship between timing of single-syllable utterances and breath support in infants around the first year of life
Introduction: The relationship between speech production and the respiratory system in infancy is not well understood. A potentially informative aspect of infant speech development is the timing between vocalization and expiration. It is an empirical question whether different utterance types are initiated and/or terminated at similar expiratory times and volumes. This study explored respiratory patterns in timing for single-syllable utterances in infants around the first year of life. Methods: Vocalizations and breathing kinematics of 10 infants between 9 and 16 months of age were recorded while the infants interacted with their mothers. Two variables related to utterance timing during the expiratory phase were measured: (a) the lag between the start of expiration and the start of the utterance, and (b) the lag between the end of the utterance and the end of expiration. Scatterplots of the two variables were used to explore patterns for both individual infants and infants grouped into a younger or older age category. Results: There were distinguishable patterns in the relationship between the timing of single-syllable utterances and the breath support. Whereas, younger infants tended to have little variability in their respiratory timing-to-utterance production patterns, older infants showed greater variability in these patterns. At least one infant in each age category had patterns that resembled those of the other group. Discussion: This study revealed that patterns in respiratory timing for single-syllable utterances in infancy are both detectable and informative. The findings help explain the relationship between breathing and vocal production late around the first year of life. Pattern variation may be explained by additional factors that might help identify atypical development in infancy via an explanatory model of normally developing infants engaged in speech production.
Thesis (M.A.)--Wichita State University, College of Health Professions, Dept. of Communication Sciences and Disorders
- Master's Theses