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Bilateral or unilateral cochlear implantation for deaf children: an observational study
  1. R E S Lovett1,
  2. P T Kitterick1,
  3. C E Hewitt2,
  4. A Q Summerfield1,3
  1. 1Department of Psychology, University of York, York, UK
  2. 2Department of Health Sciences, University of York, York, UK
  3. 3Hull–York Medical School, University of York, York, UK
  1. Correspondence to Professor A Q Summerfield, Department of Psychology, University of York, Heslington, York YO10 5DD, UK; aqs1{at}


Objective Cochlear implantation in one ear (unilateral implantation) has been the standard treatment for severe-profound childhood deafness. We assessed whether cochlear implantation in both ears (bilateral implantation) is associated with better listening skills, higher health-related quality of life (health utility) and higher general quality of life (QOL) than unilateral implantation.

Design Cross-sectional observational study.

Setting University of York.

Participants Fifty severely-profoundly deaf and 56 normally-hearing children recruited via a charity, the UK National Health Service and schools.

Interventions Thirty of the deaf children had received bilateral cochlear implants; 20 had unilateral cochlear implants.

Main outcome measures Performance measures of children’s listening skills; parental-proxy valuations of the deaf children’s health utility obtained with the Health Utilities Index Mark 3 and of their QOL obtained with a visual analogue scale.

Results On average, bilaterally-implanted children performed significantly better than unilaterally implanted children on tests of sound localisation and speech perception in noise. After conservative imputation of missing data and while controlling for confounds, bilateral implantation was associated with increases of 18.5% in accuracy of sound localisation (95% CI 5.9 to 31.1) and of 3.7 dB in speech perception in noise (95% CI 0.9 to 6.5). Bilaterally-implanted children did not perform as well as normally-hearing children, on average. Bilaterally- and unilaterally-implanted children did not differ significantly in parental ratings of health utility (difference in medians 0.05, p>0.05) or QOL (difference in medians 0.01, p>0.05).

Conclusions Compared with unilateral cochlear implantation, bilateral implantation is associated with better listening skills in severely-profoundly deaf children.

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  • Funding RESL is supported by Deafness Research UK. During this study, PTK was supported by the Royal National Institute for Deaf People. Travel and accommodation costs for participating families were reimbursed by a grant from Advanced Bionics UK Ltd.

  • Competing interests Advanced Bionics UK Ltd, a manufacturer of cochlear implants, organises an annual conference. The company has reimbursed travel and accommodation costs incurred by RESL, PTK and AQS in attending that conference. AQS has received a research grant, which funds a fellowship for PTK, from Advanced Bionics UK Ltd.

  • Ethics approval Ethics approval was provided by the North West Research Ethics Committee of NRES and by local research ethics committees in the following locations: South Birmingham, Nottingham (Committee 1), Central Manchester, Ayrshire & Arran.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Patient consent Obtained from the parents.