Age sensitivity in the acquisition of lexical tone production: evidence from children with profound congenital hearing impairment after cochlear implantation.
OBJECTIVE
This study investigated the effects of implant experience and age at implantation on the Cantonese tone production of children with cochlear implants. The study also examined whether there was a particular age at which children were more responsive to acquiring tones.


METHODS
The study included 45 children who had received unilateral cochlear implants at a mean age of 65.56 months. The subjects were grouped according to their age at cochlear implantation and were assessed annually for 5 years thereafter. A picture-naming task was used to measure their tone production performance.


RESULTS
A simple effect of age at implantation was significant at all testing intervals except at the preoperative data point. Children who were younger than 4 years of age when they received their implants scored significantly higher than did the 2 older groups at various testing intervals. A significant simple effect of implant experience was also found. Progress was most striking in children who received their implants before the age of 4 years.


CONCLUSIONS
For the most effective acquisition of Cantonese lexical tones, children should undergo early cochlear implantation. For children who receive implants before the age of 4 years, benefits are noted in tone production ability in terms of a faster rate of improvement within a shorter period of time.
Lee
Kathy Y S
KY
Institute of Human Communicative Research, Department of Otorhinolaryngology-Head and Neck Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
van Hasselt
Charles Andrew
CA
Tong
Michael C F
MC
D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003054:Cochlear Implants; D005260:Female; D034381:Hearing Loss / Q000151:congenital* / Q000628:therapy*; D006801:Humans; D007223:Infant; D007804:Language Development; D008297:Male; D010898:Pitch Perception