Is a cochlear implant right for this person?

John Holsgrove
John Holsgrove
Lize Coetzee, Audiologist, Subiaco
Lize Coetzee, Audiologist, Subiaco

Ed: Cochlear implants are becoming more commonplace and these notes will assist you with patient selection.

Hearing loss currently affects 1 in 6 Australians. GPs, through an improved understanding of the investigation and management of hearing loss, have the potential to change the lives of hundreds of Australians. Hearing implant technology is rapidly evolving so identifying patients suitable for cochlear implantation and streamlined referral can be useful.

Hearing loss impacts on personal and professional relationships, and mental health and physical wellbeing. Despite this, <10% penetration occurs in adults around the world for cochlear implantation (i.e. more than 90% of people miss out).

What is a cochlear implant?

Melbourne surgeon scientist Prof Graham Clark designed the first multi-channel ‘bionic ear’ and performed the first cochlear implant in 1977. Since then, Australian implant company, Cochlear™ has supplied more than 550,000 hearing implants across the world.

A cochlear implant is a sophisticated electronic medical device that bypasses damaged sensory hair cells within the cochlea (inner ear) to directly stimulate auditory nerves. A cochlear implant consists of two parts:

  • First, is the external sound processor; it collects and processes the sound and converts it into a radio frequency that is sent through the skin;
  • Second, is the internal implant – the receiver stimulator and electrode, which is inserted into the cochlea and provides electrical stimulation to the auditory nerve, delivering sound directly to the brain.

Who should be considered for a cochlear implant?

Cochlear implantation involves usually safe, short-stay surgery. Most recipients have moderate to profound hearing loss and poor speech discrimination in one or both ears.

The audiogram and aided speech perception are two main determinants for cochlear implant candidacy. More recently, candidacy has expanded to include one-sided hearing loss, patients with significant residual hearing but poor speech discrimination, Meniere’s disease and even patients with acoustic tumours.

Most hearing aid users should be able to communicate with family and friends, hear in a medical appointment or over the phone. If they do not, they should be re-evaluated for a cochlear implant.

Cochlear implantation should also be considered for those who do not find their hearing aids of enough help, despite programming by an experienced hearing aid audiologist.

To obtain an audiogram, speech perception results and more information on suitability for cochlear implantation refer any patient to a hearing implant audiologist. Referral to the public system directly requires an up-to-date audiogram (ww2.health.wa.gov.au/Articles/F_I/Hearing-loss), so referral to a hearing implant audiologist may be warranted beforehand.

Referral to an implant centre will determine if cochlear implantation is recommended, based on further testing.

What is the cost of a cochlear implant?

Cochlear implants can be funded both privately or publicly. For someone on gold and silver private hospital and ancillary insurance cover, they can expect no prosthesis out-of-pocket expense.

What outcomes can you expect?

The key aim of cochlear implantation is to drastically improve speech perception. As technology has improved, so have the published speech perception outcomes for cochlear implant recipient. Our research has shown that between 3-12 months post-implantation, 82% of the recipients score above 90% on tests of sentence understanding.

Key Messages

  • A cochlear implant aims to improve speech perception.
  • Candidates also include those with unilateral hearing loss, Meniere’s disease and poor speech understanding.
  • The first step is an audiogram and assessment by an implant audiologist.

The author wishes to acknowledge the assistance of Prof Marcus Atlas for assistance in compiling this article.

References available on request.

Questions? Contact the editor.

Author competing interests: nil relevant disclosures.

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