Optimizing outcomes for hearing impaired children

Lead Research Organisation: MRC Institute of Hearing Research

Abstract

Children who are profoundly deaf benefit from the use of a cochlear implant (CI), a device surgically implanted in the inner ear. The success of CI has led to the suggestion that implants in both ears may produce even better results, especially for spatial hearing that depends on listening with both ears. We are testing that idea in a small number of children who are now receiving two implants. Unfortunately, the language development of some children who receive a CI does not progress as well as it might and, more generally, the outcome for many CI users remains poor, despite impressive advances in recent years. We are trying to understand why this is so and it appears that some CI users have language problems, just like normally hearing children. This suggests the use of similar treatment. One promising form of treatment is auditory learning, which we have shown improves language skills in normally hearing children. We also have some evidence of improvements in a couple of CI users. We will develop this treatment, which is based on practicing computerised listening games, for the benefit of all CI users. We anticipate that auditory learning will provide a common method for the treatment of all hearing problems.

Technical Summary

Hearing losses are treated in many different ways, depending on the type of loss and a range of other factors. However, all forms of hearing loss share at least two common treatment principles. The first is that understanding the characteristics of the individual's hearing, both before and after treatment, is of fundamental importance in assessing the nature of the loss, the impact of the treatment and the design of new treatments. The second is that teaching the individual to make optimal use of the hearing they do have will result in the best possible outcome. In this Strand, we are addressing these principles by examining hearing in listeners who have cochlear implants and by developing methods of auditory training that we hope will be applicable to treatment of a broad range of hearing problems, from middle ear disease to profound deafness.

People who have received a cochlear implant (CI) are likely to have great difficulty with spatial hearing. Because this depends strongly on the integration of information from the two ears. One of the hopes for bilateral implantation, which has been used in limited numbers, is that spatial hearing will be greatly improved. We have begun testing that hypothesis by examining spatial hearing in unilateral and bilateral CI users, as well as in matched, typically-hearing controls. This work focuses on children, for whom special test methods have been developed. A future focus will be the effect of training. Can we improve spatial hearing through practice? Methods for the training work will depend heavily on other IHR research on auditory learning.

It has been observed that some CI users have difficulty with the acquisition of language skills that is disproportionate to their ability to detect tones. We have some evidence that these CI users have a 'disproportionate language impairment' (DLI), using standard tests that have been used to diagnose language impairment in typically hearing listeners. We are now studying further cases, but the results suggest that poor outcomes in CI may often be attributable to an underlying, possibly iherited language disability. We are currently examining this idea using questionnaires about hearing and language of normally hearing relatives of the CI users who have DLI.

Auditory learning holds out hope for the treatment of a range of hearing impairments. We have already shown that practicing a phoneme discrimination task can improve phonological awareness, a broad-based language listening measure, in typically hearing children, and evidence from a few CI users provides encouragement that it will also be useful for CI habilitation. We intend to extend those findings in other CI users and, in the longer term, using other training tasks. Initially these will be developed in typically hearing children, and the results will be applied to children diagnosed with middle ear disease, auditory processing disorder, and sensorineural hearing loss.
 
Description Health economics training
Geographic Reach Multiple continents/international 
Policy Influence Type Influenced training of practitioners or researchers
Impact Training of practitioners in aspects of cochlear implantation health economics
 
Description NICE review of cochlear implants
Geographic Reach Multiple continents/international 
Policy Influence Type Participation in a national consultation
Impact Directly informed NICE policy on cochlear implantation
 
Description NIHR Biomedical Research Unit
Amount £3,750,000 (GBP)
Organisation National Institute for Health Research 
Department NIHR Biomedical Research Unit, Nottingham University Hospitals NHS Trust
Sector Public
Country United Kingdom
Start 03/2008 
End 03/2012
 
Description NUHT partnership 
Organisation Nottingham University Hospitals NHS Trust
Country United Kingdom 
Sector Academic/University 
PI Contribution Experimentation on patients. Lead role in analysing and presenting papers
Collaborator Contribution Provision of patients who have received cochlear implants
Impact Informed NHS policy and influenced world practice
 
Description Presentations to health service professionals 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Primary Audience Health professionals
Results and Impact Information, industry-sponsored and CME training of health professionals

Familiarisation of professionals with latest research on outcomes and health economics of cochlear implantation
Year(s) Of Engagement Activity 2006,2007