Speech production outcomes in young children with early identified hearing loss

Relevant acoustic and linguistic information is not accessible to young children with a damaged or absent sense of hearing. While infant hearing screening enables early instrumentation and intervention for children with hearing loss, they have shown a substantial amount of variability in speech production outcomes. Comprehensive analysis of speech outcomes using contemporary speech and language measures is pivotal to specifying the diversity of speech characteristics in addition to understanding the relationship of auditory input system and production output system capacities. Speech characteristics in spontaneous speech output of children with hearing loss were examined by analyzing associations across multiple speech and language measures, relationships of speech accuracy with input factors of phonotactic probability and neighborhood density, and speech intelligibility as perceived by adult listeners. Spontaneous connected speech samples were collected for twenty-one children with bilateral cochlear implants or hearing aids. Results revealed a largely consistent chronological age-related developmental pattern across the speech measures and mean length of utterance (MLU). Most of the children demonstrated a delay in acquiring later developing consonants and more complex word forms. Based on individual variance in performance across analysis measures, environmental factors contributing to individual differences in their speech production include chronological age at receiving instrumentation and familiarity of the speech sampling context. Phonotactic probability and neighborhood density showed positive relationships with consonant accuracy in CVC word forms produced. Vowel accuracy in CVC word forms was negatively related to neighborhood density in this cohort. Intelligibility outcomes were highly associated with speech measures, suggesting the importance of a whole-word analysis approach. These results emphasize the importance of analyzing functional daily communication interactions in children fit early with HA or CI instrumentation. Findings support use of measures that can reveal the sources of reduced intelligibility.