Cochlear Implants for severe to profound hearing loss

Children who have severe to profound hearing loss can often experience delays in learning to talk. Early intervention, such as fitting a hearing aid or provision of a cochlear implant is critical for giving a child access to sound to learn to speak.  Lifelong disadvantage can result from inadequate hearing care by reducing a person’s ability to communicate and participate in society.

In many cases of children with a severe to profound hearing loss, hearing aids are unable to effectively provide the access to speech sounds that is needed for oral language development. Therefore, children in this situation need to undergo assessment to determine their candidacy for cochlear implants. A cochlear implant can offer the necessary physiological stimulation for profoundly deaf children that hearing aids are unable to provide.

The challenge with this process is multifactorial. One factor is that specialized audiology clinics offering these services are limited, especially in developing countries.

Another is that current audiology practices primarily rely on electrophysiology measures (a response from the auditory nerve in the brain) in young infants to determine how to accurately program a hearing aid. This kind of testing is not effective for all types of hearing loss.

Assessing the benefit of hearing aids for a child can also be challenging, and can only be performed accurately once the child is developmentally ready for behavioural testing. By the time this is possible, the child may have already missed a crucial period in their life for language acquisition, even if they have been using a hearing aid.

Furthermore, globally, there is no method to assess whether an infant can tell the difference between different speech sounds. Such a test would help audiologist to know much earlier whether a cochlear implant would be better than a hearing aid for a severe to profoundly deaf child.

Recently, researchers at the Bionics Institute have created a speech discrimination test for infants. It is an objective test that this will assist Audiologists in the decision-making process of whether child needs a hearing aid or cochlear implant. It will also be used to ascertain if a child is hearing adequately through their hearing aid.

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Sharma SD, Cushing SL, Papsin BC, Gordon KA. Hearing and speech benefits of cochlear implantation in children: A review of the literature. Int J Pediatr Otorhinolaryngol. 2020 Jun;133:109984. doi: 10.1016/j.ijporl.2020.109984. Epub 2020 Mar 9. PMID: 32203759.
Entwisle LK, Warren SE, Messersmith JJ. Cochlear Implantation for Children and Adults with Severe-to-Profound Hearing Loss. Semin Hear. 2018 Nov;39(4):390-404. doi: 10.1055/s-0038-1670705. Epub 2018 Oct 26. PMID: 30374210; PMCID: PMC6203457.
Ching, T.Y.C., et al., Learning from the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study: summary of 5-year findings and implications. Int J Audiol, 2018. 57(sup2): p. S105-S111.
Linty McDonald, Research Audiologist at the Bionics Institute, East Melbourne, VIC, Australia.