University of Edinburgh

Outcomes of Paediatric Cochlear Implantation

Presented in February, 2005

The order of those things we know about deaf pupils with cochlear implants

Ernst Thoutenhoofd

This presentation was first delivered at the University of Central Lancashire (Deaf Studies seminar), 22 February 2005; and at the Scottish Sensory Centre CPD course on outcomes of paediatric cochlear implantation, 23 February 2005.

International literature review, 1994?2002 Thoutenhoofd, ED, Archbold, SM, Gregory, S, Lutman, ME, Nikolopoulos, TP and Sach, TM (2005) Outcomes of paediatric cochlear implantation. London, England: Whurr. ISBN 1-86156-366-3. Project funded by Cochlear International.

Areas of interest
  • Language and communication (spoken and sign languages).
  • Family and social life.
  • Education, placement and attainment.
  • Health economics.


To summarise the current knowledge on this topic and identify gaps in the literature.

To make recommendations for future research in the area, identifying aspects of benefit not previously taken into account.

Coverage (selection criteria for inclusion)

Published in English.

Research conducted after 1994, in order to exclude single-channel implants.

Sample sizes of ?12 children or parents.

Databases were searched twice, at start and end of the project. The review covers 145 accounts, from 248 originally identified.

Journal spread

Most articles appeared in medical journals, and searches through Medline were the most productive. Other sources were BEI/ERIC, CINAHL, IBSS, PsycInfo and Web of Science.

104 key words and reported measures were listed against the collection of articles.

Key findings

  • Speech recognition and speech perception are the most researched outcomes.
  • Studies generally report wide variation in individual performance.
  • Demographic reporting focuses mostly on audiological, implant and placement measures.

General finding

"Relative to the huge range of factors that may affect outcome [?], there is a more general under-analysis of demographic sample characteristics and few attempts at factoring out intervening variables. Hence any number of outside factors might help to explain individual variation." (:21)

General conclusion

Outcomes may be divided into 3 categories:

  • Robust outcomes eg; improved auditory performance
  • Inconclusive/contradictory outcomes eg; language development; placement
  • Outcomes with little or no research eg; educational outcomes; quality of life

Selected conclusions

"? the perceptual effect of the implant is equivalent, on average, to an improvement of about 28dB in hearing thresholds." (Blamey et al. 2001:264)

"?the average language delay will be about 4 or 5 years by the time the children enter secondary school at about age 12 years." (:283)

Achievements of Deaf Pupils in Scotland Project (ADPS), 2000?2005
Mary Brennan (Director), Marian Grimes, Emily Healy, Claire Leiper, Ernst Thoutenhoofd.
Project funded by Scottish Executive Education Department.

The goal of ADPS

The ADPS project is longitudinal in intent, tracking the educational situation and performance of most deaf pupils in Scotland specifically in order to identify factors that help explain the over-time expression of adverse effect on achievement. Questionnaire return rates for the four years are well over 95%.

The ADPS population, 2000?2005
1,922 pupils in the database
5,272 year records
19,781 attainment records
Details at 12 February 2005.
Nb: the information on the slides that follow is ?work in progress?, much in the spirit of this seminar/workshop. The tables have not been checked by the ADPS team, and therefore any errors that may exist are entirely my own. For data published through the project, consult the ADPS website.

graph of reading age percentages

graph of reading age percentages