Ask The Experts

Consider cochlear implants for severe hearing loss

Q. My 89-year-old mother has had hearing impairment for more than 10 years. We have to go close to her and talk slowly so that she can hear us.

She had hearing aids fitted a year ago but complained about background noises. She hardly uses them.

Would cochlear implant surgery be suitable for her?

A. It is very common for elderly people to develop hearing loss due to the degeneration of the hearing organ (cochlea).

This condition is known as presbycusis.

At the start, the person may have difficulty hearing certain higher- frequency sounds. Eventually, he will have problems with hearing in general.

In view of your mother's age, it is likely that she has presbycusis.

She may also have a more severe form of hearing loss that is caused by a different medical condition. It is thus important for her to be evaluated by an ENT (ear, nose and throat) surgeon.

The evaluation would start with a comprehensive history-taking session and clinical examination.

This helps to ascertain whether the disease is in the external ear, middle ear, inner ear or a combination of the three.

The next step in the evaluation is a series of hearing tests, including pure tone audiometry, which can determine the severity and pattern of hearing loss.

It is often necessary to augment these tests with more advanced hearing tests, such as speech audio- metry and aided threshold audiometry, to determine if the use of hearing aids is likely to benefit the person's hearing.

In certain patients, the hearing loss is so severe that hearing aids are not likely to offer sufficient listening benefit.

In these instances, the use of surgical hearing implants, including cochlear implants, can be considered.

As your mum already has hearing aids, it is important for her to do a series of tests with them.

These include the aided threshold pure-tone audiograms and the aided speech-discrimination score, which will help determine whether her hearing aids are optimally tuned.

If they are not, the hearing aids should be programmed digitally to provide sufficient amplification at the correct hearing frequencies.

After this, she should repeat the tests that I mentioned earlier.

If the tests show that the optimised hearing aids did not improve her hearing, then she is likely to be a candidate for surgical hearing implants, namely, a cochlear implant.

Cochlear implants restore hearing by directly stimulating the nerve endings of the hearing nerve in the cochlea.

They have been shown to be of significant benefit to patients who have severe to profound sensori- neural hearing loss (hearing loss due to damage to the cochlea) and who are not adequately helped with hearing aids.

There is plenty of evidence to show that cochlear implants offer very good hearing benefits in the elderly.

The technology has evolved over the past 35 years.

Cochlear implant devices that are available today are extremely small and easy to use, and they also provide exceptional hearing function.

I would recommend that your mum consult a cochlear implant surgeon to discuss her suitability for this operation.

Dr Barrie Tan

Head & senior consultant, department of otolaryngology, and director, Singapore General Hospital Centre for Hearing and Ear Implants.

A version of this article appeared in the print edition of The Straits Times on January 17, 2017, with the headline 'Consider cochlear implants for severe hearing loss'. Print Edition | Subscribe