The first few years of speech-language development are formative in setting the stage for later communication abilities. Coinciding with early speech-language development is the emergence of other behaviors, including the complex sensorimotor processes involved in feeding (suck, drink, chew, swallow). Even though feeding and communication share considerable neural resources and muscle systems, the link between them remains poorly understood. Previous empirical evidence suggests that feeding and speech are distinct in their goals and muscle activation patterns. However, it remains unclear how performance and ability on these skills are related in the first year of life and if delays in one oromotor behavior manifest as delays in another. No prospective studies to date are available to compare healthy and preterm infants in regards to mapping the association between feeding and the emergence of vocal development. Therefore, the objective of this application is to examine how sucking, oral feeding, and vocal development co-occur in the first year of life. In the proposed research, we will longitudinally (sessions at 3 and 12 months) study two cohorts of infants (n=100): those born full-term (n=50) and those born preterm (< 37 weeks gestational age; n=50). The goals of the proposed research are to examine whether sucking ability (Aim 1), as measured quantitatively by sampling non-nutritive suck (NNS) patterning, and oral feeding abilities (Aim 2), as measured quantitatively by the Oral Feeding Skills (OFS) scale, are associated with infant vocal development over the first year of life. We will also compare sucking, feeding and vocalization measures based on birth group (Aim 3). In each of the aims, infant vocalizations will be measured using the Language Environment Analysis (LENA) system during full day recordings of the child's home auditory environment. LENA will yield the following measures: vocalization rate, percentage time vocalized, canonical syllable ratios (12 months), and phonetic inventories (12 months). We will also have parents complete Part 1 of the McArthur-Bates Communication Development Inventory (CDI) at 12 months. We hypothesize that infants with well-patterned NNS and mature oral feeding skills will have higher vocalization rate, greater percentage time vocalized, increased canonical syllable ratios, more complex phonetic inventories, and higher CDI scores with full-term infants performing better across these measures. Several features of this study provide an unprecedented level of power for identifying the connection between early oromotor behaviors and vocal emergence, including longitudinal design, quantitative oromotor assessments combined with behavioral data collected in the infant's natural environment, and a comparison of these behaviors across two cohorts. Findings from this work could have broad implications for advancing the field of speech science, and an immediate impact on clinical feeding and speech therapy. More specifically, the proposed studies are likely to determine whether sucking and feeding can be used as a prognostic indicator of vocal development, thereby shifting how clinicians approach feeding and speech assessments and therapies.
Even though feeding and communication skills share considerable neural resources and muscle systems, they are rarely studied together and the link between feeding and vocal development remains poorly understood. The goals of the proposed research are to determine the association between sucking (Aim 1), oral feeding (Aim 2) and infant vocal development (Aims 1, 2, 3) over the first year of life (two study sessions: 3 and 12 months), and to determine how these behaviors differ between full-term (n=50) and preterm infants (n=50) (Aim 3). Findings from this work will advance our understanding of using sucking and feeding as a prognostic indicator of vocal development, and will shift how clinicians approach feeding and speech therapies.