The prelexical development in children implanted by 16 months compared with normal hearing children

Summary 

Objective

Few studies exist which document the early speech development of German-speaking children or German-speaking children who are deaf and using cochlear implants. The current study aims to: (1) document the pre-canonical and canonical speech development of German-speaking children who are deaf and receive cochlear implants by the age of 16 months and (2) compare these children's results with those of children with normal hearing.

Design

This longitudinal study included 5 German-speaking children with normal hearing and 5 with sensorineural deafness. All children from the deaf group received hearing amplification before cochlear implantation, received their first implant by 16 months of age, and became bilateral implant users by 31 months of age. The pre-canonical and canonical vocalisations of each child were recorded on video- and audiotapes in a semi-standardised playing situation every 4 weeks over a span of 1 year. In the cochlear implant group, the recording started 4–5 days postoperatively (first implant); in the normal hearing group it began between the ages of 4 and 5 months. The video and audio recordings were analysed using EUDICO Linguistic Annotator version 2.4 (Nijmegen, The Netherlands) and International Phonetic Alphabet transcription.

Results

Both groups showed individual patterns of babbling acquisition, though the groups’ patterns of acquisition were similar when analysed for consonant manner and place. Some children started with plosives and others, with nasals, but all acquired fricatives and laterals next. Onset of canonical babbling for children in the cochlear implant group began 0–4 months after first fitting of the first device, while children from the normal hearing group demonstrated an onset of canonical babbling between 4 and 9 months of age.

Conclusion

Our results show that deaf children who receive cochlear implants at an early age are capable of reaching the canonical babbling milestone in a shorter time than children with normal hearing typically do and that their consonant phoneme acquisition follows a similar sequence to normal hearing peers’. These results are consistent with the literature indicating that early identification and intervention are important for allowing children with cochlear implants the opportunity to catch up to hearing peers.

Keywords: Cochlear implants, Speech production, Vocal development, Canonical babbling, German language development, Age at implantation