Cochlear Implants

Cochlear Implants help people who have at least a moderate to profound sensorineural hearing loss and are no longer receiving enough help from their hearing aids. Hearing aids amplify sound, making the sound louder. The ear with a sensorineural hearing loss may not be able to process the information due to damaged hair cells. Despite hearing certain sounds, speech remains unclear. Even the most sophisticated and powerful hearing aids may not help these people.  In contrast to a hearing aid, which simply makes sounds louder, a cochlear implant takes the place of parts in the inner ear, or cochlea, which are not working properly.

How does a Cochlear Implant work?

A cochlear implant comprises of:

Microphone –sound is recorded by the microphone.

Speech processor - the sound is converted to coded signals by a sophisticated internal chip.

Transmitting coil - this coil sends the signals across the skin to the internal implant.

Implant - the implant sends the signals to the electrode array to stimulate the hearing nerve fibres in the cochlear.

Surgery is carried out through a small incision behind the ear to expose the underlying bone. The skin is raised from the skull bone and the implant is placed against the bone behind the ear. A hole is made into the ear bone providing access to the organ of hearing (cochlea). A tiny hole is made into the wall of the cochlea and the electrode array is gently placed into the shell shaped cochlea.

X-rays or electrical testing is carried out to verify the implant position. The cochlear implant operation usually takes about 1 1/2 to 3 hours to complete and the patient is usually discharged from the hospital on the day following surgery.

Cochlear implant programming and rehabilitation

After surgery it generally takes 2 weeks for the incision to heal. The implant recipient is then fitted with the external components called the speech processor.

Following surgery patients require a rehabilitation programme to help them and their families use the cochlear implant in everyday life. The Lions Hearing Clinic provides expert cochlear implant services to allow patients to develop hearing and listening abilities leading to new communication skills.

Electro-Acoustic Stimulation

Combined Electric Acoustic Stimulation, or EAS, is the concept of applying acoustic amplification and cochlear implant technology together in the same ear. It is the first hearing system worldwide combining both a cochlear implant and digital hearing aid technology. It is designed for people with mild to moderate low frequency hearing loss combined with a profound hearing loss in high frequencies.

EAS™ is a relatively new option for people with residual low-frequency hearing coupled with high-frequency hearing loss often referred to as a ski-slope hearing loss. Hearing aids often provide unsatisfactory results in understanding speech or listening to complex sounds such as music for a person with this type of hearing loss. Traditional cochlear implant systems are also not ideal because they do not allow users to benefit from their residual natural hearing of low frequency sounds.

The DUET EAS™ Speech Processor features acoustic amplification that supports a person’s natural residual hearing in the low frequencies and for the higher frequency sounds, the DUET’s cochlear implant function automatically takes over. The result is a synergistic effect offering the benefits of both types of hearing technologies.

One of the key factors for preserving residual hearing are specially designed electrodes. It is essential to protect the fragile structures within the cochlea from damage during electrode insertion. The FLEXEAS electrode array is specifically designed for the requirements of the EAS™ Hearing System. The surgery and rehabilitation process is very similar to traditional cochlear implantation mentioned above.

Middle Ear Implant- The Vibrant Sound Bridge Device

The partially implantable device is an alternative to conventional hearing aids for people who cannot physically wear hearing aids in their ear canals. With the Vibrant Sound Bridge Device there is nothing worn in the ear canal. The implant is attached to one of two areas in the middle ear depending on the type of hearing loss.

For a mild to severe sensorineural hearing loss it is placed on the incus (one of the middle ear bones) which mechanically causes the middle ear structures to vibrate.

For a mild to severe mixed or conductive hearing loss the floating mass transducer is placed on the round window of the cochlear.

The Soundbridge® consists of two major components:

Implant which is called the Vibrating Ossicular Prosthesis (VORP)

Audio Processor the external amplification system. It is a digital device attached to the head via a magnet and is programmed by our Audiologists. The device is activated 4 to 8 weeks after the implant procedure to fit the user's specific hearing loss. Adjustments are easily made to suit the users preference, much like a normal hearing aid.

If you decide to investigate any of the above devices further, the next step is a clinical evaluation to determine if you are a suitable candidate.

For more information contact:

Lions Hearing Clinic - Implant Centre
ph. 6380 4949
fax. 6380 4950 
email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Links:

Cochlear Ltd
One of the suppliers of various implants in Australia.
www.cochlear.com.au

Med-El
Another of the suppliers of various implants in Australia.
www.medel.com

CICADA
A non-profit self-help group for people with cochlear implants and those who are considering having surgery.
www.earscience.org.au/cicada

Advanced Bionics
www.cochlearimplant.com

Medtel
www.medtel.com.au