Southern ENT - Nucleus Clinical Information

Nucleus Clinical Information

What is a cochlear implant?

A cochlear implant is a tested and proven medical intervention to connect clinically approved hearing impaired people to sound, providing that the hearing nerve between the brain and cochlea still works. It restores hearing levels to between 20 and 30 dB, which is normal hearing thresholds. Unlike hearing aids, which make sounds louder, it replaces the function of the damaged inner ear (cochlea).

Who qualifies?

Early implantation is of utmost importance as it influences a child’s ability to develop spoken language. Cochlear implants are routinely implanted in children from 12 months of age. The youngest person in South Africa to receive a cochlear implant is 7 months.
Cochlear implants can help adults who:

have moderate to profound hearing loss in both ears
receive little or no benefit from hearing aids
score 50% or less on sentence recognition tests in the ear to be implanted
score 60% or less on sentence recognition tests in the non-implanted ear or in both ears with hearing aids

and children who:

have severe to profound sensorineural (inner ear) hearing loss in both ears and
receive no real hearing benefit from hearing aids and
are not making progress in developing speech and
have parents and families dedicated to their child learning speech and being part of the hearing world

See referral criteria for professionals under ‘downloadable content’ on the PROFESSIONALS page.

How does a cochlear implant work?

A receiver-stimulator is placed just under the skin, behind the ear
An electrode array is implanted surgically into the cochlea
An external sound processor transmits digitally-coded sound to the cochlea
The recipient manages his/her hearing with a hand held remote assistant

What are the benefits of a cochlear implant?

Children: Cochlear implants for children
Adults: Cochlear Implants for adults

Frequently asked questions

We asked a few cochlear implant units to answer some of the questions they often get:

What symptoms are there for a child who is having trouble with hearing at infancy?

Symptoms vary by age:

A newborn baby may not startle when a loud noise sounds nearby.
Older infants may show no reaction when spoken to.
Children should be using single words by 15 months, and simple 2-word sentences by age 2. If they do not reach these milestones, they might experience hearing loss.

Some children may not be diagnosed until they are in school. This is true even if they were born with hearing loss. Inattention and falling behind in class work may be the result of an undiagnosed hearing loss problem. Children learn to communicate by imitating the sounds they hear. Untreated hearing loss results in delayed speech/language development, social problems and academic difficulties. (Johannesburg Cochlear Implant Clinic)

What is the ideal age to implant a young child?

The ideal age for a child to be implanted if the child is born with bilateral severe to profound hearing loss is before the age of one year. The research comparing age at implantation and outcomes is clear that the earlier a child is implanted the better the outcome. The reason for this is that in children with normal hearing the brain is learning all about sound even in utero, so the longer the delay in providing the child with meaningful sound the bigger the delay will be in the acquisition of spoken language. Outcomes can still be good if the child is implanted before the age of two years, but if the child has no language by the age of 3 years and then receives a cochlear implant it will be difficult to overcome that delay. Rehabilitative intervention is critical in a better outcome. (Tygerberg Hospital Cochlear Implant Unit)

Do you ever put the implants in both ears? Why or why not?

Most of the implantees at our clinic are young babies and children, and as such we see most children with bilateral profound hearing loss. Many times we recommend bilateral implants to:

ensure that the dominant pathway is being stimulated;
assist with binaural processing skills, which includes localization of sound as well as processing of speech in noise

Difficulties to consider include financial constraints, traumatic histories or surgical risks. In Durban, we have recently successfully performed our first two bilateral simultaneous implants on two young children, and recently performed a bilateral sequential implant on an adult who was a long term hearing aid user. Many patients express the desire to implant the other ear to obtain better balance, and to not feel “lopsided”. (Durban Cochlear Implant Program)

What is the success rate of cochlear implants, and what is considered a success?

The selection criteria (see ‘who qualifies’ under the CLINICAL INFORMATION page) determines to a large extent the success that can be achieved with a cochlear implant. Pre-operative expectations determine post-operative outcomes.
The vast majority of recipients become successful users although a wide range of results occur and cannot be described by a single measure.
Adult with acquired hearing loss often benefit immediately after the activation of the electrodes and many understand speech without lip-reading on the first day already. More than 70% can be employed in an environment that requires the use of a telephone.
Children, born deaf, who received a cochlear implant before the age of 2 years, have the potential to enter grade 1 with spoken language skills that closely match those of their hearing peers – providing there are no other factors influencing the child’s progress and the child receives the required speech and language therapy. (Tygerberg Hospital Cochlear Implant Unit)

How effective is the implant in allowing a child to hear at normal levels?

Hearing is uniquely different for everyone, almost like a fingerprint. There are many factors that will influence how well a child will hear with a cochlear implant. These include aspects like the duration of hearing loss, condition of the inner ear and other medical conditions, rehabilitation and practicing hearing with the cochlear implant. Once the device has been fitted optimally, a child should be able to detect sound and speech between 20dB and 30dB. However, providing a cochlear implant does not imply that the child will automatically be able to perceive or interpret all the new sounds. Learning to listen with the cochlear implant is therefore of utmost importance to ensure a successful outcome. (University of Pretoria Cochlear Implant Unit)

Back to CLINICAL INFORMATION