Predicting Phonological Outcomes in Late Talkers: the Role of Speech Perception and Production Skills - PROJECT SUMMARY/ABSTRACT Late talkers (LTs) are a heterogeneous group of children who display delays in their expressive vocabulary development in the absence of neurodevelopmental disorders.1 In addition to their delays in vocabulary growth, LTs frequently show delays in multiple areas of phonological development. These delays include a later onset of canonical babbling,2 reduced phoneme inventory,3 reduced syllable structure inventory,4,5 and the presence of atypical phonological patterns.6 Up to 50% of LTs will later be classified as having a speech-sound disorder (SSD),2,5,7 with associated negative developmental outcomes including delays in preliteracy skills,8 phonological awareness,9 and psychosocial difficulties.10 While effective early speech-sound interventions exist for young children,11 current diagnostic measures cannot accurately forecast which LTs will later develop SSD, making it difficult to efficiently allocate intervention resources early to mitigate these negative outcomes.12 To become competent language users, children must become adult-like in both speech perception, (e.g., the ability to differentiate between speech sounds), as well as in speech production (i.e., the ability to accurately produce speech sounds). LTs’ early phonological delays could be due to underlying difficulties in either speech perception, speech production, or both. The primary objective of the proposed project is to explore patterns among speech perception and production abilities amongst children with a history of LT and whether these skills predict later phonological development and the presence of SSD. A large group of both LTs and typical talkers will complete study visits at 3 and 4 years of age. At age 3, we will measure speech perception using a pupillometry mispronunciation task. At age 3 and 4, we will measure speech production using fine-grained acoustic analyses of children’s speech productions that can detect subtle articulatory differences that may be missed on perceptual-based measures. Aim 1 will assess the concurrent relationship between speech perception and production on both early-acquired (/k/-/t/) and later-acquired (/s/-/ʃ/) sounds at age 3. Aim 2 will assess the degree to which age-3 speech perception and speech production skills predict age-4 speech production skills. Aim 3 will utilize latent profile analyses to identify unique profiles of speech perception and speech production skills at age 3 that predict the presence of SSD at age 4. This project will contribute to current theoretical models of speech production by empirically testing the association between perception and production both concurrently and longitudinally and will identify profiles of skills at age 3 that can be used to assess risk for later SSD.
