Introduction:
Before young children are given their cochlear implant their communication tends to be mainly visual and silent.
After implantation we expect them to move gradually towards a more vocal and auditory mode.
This change can be measured by making video recordings of the children in interaction with someone they know well, and analysing transcripts of the recordings.
The aim of this study was to compare 3 groups of children, implanted at 1+ (1.0 – 1.11), 2+ (2.0 – 2.11) and 3+ (3.0 – 3.11) to see what progress they made in auditory processing of speech.
Materials and Methods:
The children were each videoed with a familiar adult, to see what percentage of their vocal responses was made when they had not been in eye contact with adult. A child who responds vocally to the adult in this way, without being prompted visually, is making an auditory response as well as a vocal one.
This is called a Non-Looking Vocal Turn (NLVT). The mode of communication used by the child before implantation and 12 months after implantation was also noted.
Results:
Before implantation all 3 groups had a very low percentage of NLVT, though statistically the 2 older groups were slightly ahead of the youngest group.
At the 6 month and 12 month intervals after implantation the 1+ group scored significantly higher than both the 2+ and 3+ groups, the probability being p<0.0001 at each comparison point. The difference between the 2+ and 3+ groups was not significant at any point.
Before implantation all 3 groups were predominantly using Total Communication rather than Oral/Aural (1+ 76%; 2+ 79%; 3+ 85%); 12 months after implantation the 2+ and 3+ groups had shown very little change, whereas of the 1+ group only 15% were still using Total Communication.
Conclusions:
The findings indicate that the children in this study who received cochlear implants under the age of 2 show more vocal and auditory ability (as measured by NLVT) than those implanted between 2 and 3 or between 3 and 4, and that there is no apparent difference between the 2 older groups.
Earlier research (Tait et al, 1997) has shown that this vocal/auditory ability is strongly related to better outcome measures of speech perception 3, 4 and 5 years after implantation.
This would seem to put very young implanted children in a good position for subsequent development of spoken language.
Whether it will give them a permanent advantage remains to be shown.
Margaret Tait is currently using video analysis to compare young deaf children who have two implants with those who have one. This project is also funded by Deafness Research UK.
References:
1. M Tait, ME Lutman, TP Nikolopoulos, Communication development in young children: review of the video analysis method, International Journal Pediatric Otorhinolaryngology 61 (2001)
2. M Tait, ME Lutman, The predictive value of measures of preverbal communicative behaviours in young deaf children with cochlear implants, Ear Hear 18 (1997)
