Vocal and early speech development in Korean-acquiring children with hearing loss and typical hearing

This study investigated the vocal and early speech development of Korean-acquiring children with hearing loss (HL) who underwent early auditory amplification compared to their typical hearing (TH) counterparts. The research focused on phonological characteristics of child vocalisation based on samples collected from naturalistic home environments. One-day home recordings using a Language ENvironment Analysis (LENA) recorder were obtained from 6 children with HL and 12 children with TH who ranged from 17 to 23 months of age in Korean monolingual environments. Child volubility, canonical babbling ratio (CBR), consonant distributions, and utterance structures of vocalisations were evaluated through qualitative and quantitative analyses of vocalisation samples collected from LENA recordings. The findings revealed that children with HL displayed comparable vocalisation levels to children with TH, with no significant differences in volubility and CBR. In consonant and utterance shape inventories, noticeable quantitative and qualitative differences were observed between children with HL and those with TH. The study also suggested both universal and language-specific production patterns, revealing the early effects of ambient language on consonant distributions and utterance structures within their vocalisation repertoire. This study emphasised the role of auditory input and the importance of early auditory amplification to support speech development in children with HL.