Naturalistic coding for prelinguistic speech at 9 and 12 months of age from two Mandarin-learning children differing in auditory function

Abstract

This study investigated the feasibility of Fagan’s (2005) naturalistic coding system for prelinguistic speech of Mandarin-learning children. This system includes 10 categories: single vowel, single consonant, consonant combination, vowel combination, syllable containing glottal sound and vowel, syllable containing supra-glottal consonant and vowel (SGCV), reduplicated vowel, reduplicated consonant, reduplicated CV, and reduplicated “SGCV" (RSGCV). The first 50 clear utterances produced by one normal-hearing (NH) child and one hearing-impaired (HI) child in the audio recordings at 9 and 12 months old were transcribed into 10 categories for comparison. Major findings are (1) compared with NH child, HI child demonstrated no obvious changes in vocalization from 9 to 12 months old; (2) at 12 months old, canonical babbling ratio of HI child was 0, while those of NH child were 0.84 (utterance as unit) and 0.48 (syllable as unit); (3) compared with NH child, HI child did not manipulate supra-glottal sounds and had limited consonant inventory; (4) HI child produced no RSGCV (e.g., /baba/) while NH child was at reduplicated babbling stage at 12 months old. Naturalistic coding system revealed difference in prelinguistic speech between a NH child and a HI child. More participants should be included to verify the findings.