Singapore General Hospital provides cochlear implant services as one of the many specialised programs available under the ENT Centre. There is a team of dedicated professional staff and ENT specialists who work together to provide our patients with the best possible medical, audiological and (re)habilitative care.
The service, which started in 1998, has seen more than 350 patients (adults and children) successfully implanted with the device.
Patients under this programme are referred to our Auditory Verbal Therapy for therapy sessions. Below are some of the frequently asked questions .
What is a Cochlear Implant?
The Cochlear Implant is a device which is implanted into the inner ear, providing useful hearing to those with total or severe to profound sensory (inner ear) hearing loss.
It is not an ordinary hearing aid, but an electronic device that bypasses the damaged parts of the inner ear to stimulate the remaining auditory nerve fibres. Part of the cochlear implant is implanted under the skin in a surgical procedure.
How does a Cochlear Implant work?
With reference to the diagram above:
- Sounds enter the Cochlear Implant system through small microphones on the speech processor(A) which is worn on the ear. The speech processor selects and codes the elements of sound that are most useful for understanding speech. These electronic codes are sent back through the cable to the transmitter (B)
- The transmitting coil (B), sends the codes across the skin to the receiver/stimulator.
- The receiver/stimulator (C) contains a custom-designed integrated circuit that converts the codes into special electronic signals and sends them along the electrode array.
The electrode array is a set of 22 tiny electrode bands, arranged in a row inside a piece of tapered flexible silicone tubing. Each electrode has a wire connecting it to the receiver/stimulator.
- The coded electronic signals are sent to specific electrodes, each of which has been separately programmed to deliver sounds that can vary in loudness and pitch. These electrodes then stimulate the appropriate hearing nerve fibres(4), which send the messages to the brain.
Guidelines for Cochlear Implant Candidacy in Children
1. Severe to Profound sensorineural hearing loss in both ears
2. Age 1 year and older
3. No medical or radiological contraindications
4 In certain conditions infants younger than 1 years may undergo
Cochlear Implantation
4. Evidence of auditory nerve function
5. Little or no benefit from hearing aids after minimum 3-6 months of hearing aid trial with appropriate amplification and (re)habilitation
6. Appropriate motivation and realistic expectation from child’s family
7. Family support and commitment towards post-implant (re)habilitation and follow-up management
Guidelines for Cochlear Implant Candidacy in Adults
1. Severe to Profound sensorineural hearing loss in both ears.
2. No medical and radiological contraindications
3. Evidence of auditory nerve function
4. Little or no benefit from hearing aids with appropriate amplification
5. Appropriate motivation and realistic expectations by patient, family and friends
6. Committed towards post-implant (re)habilitation and follow-up assessments
What are the benefits of having a Cochlear Implant?
Speech and other sounds from the cochlear implant will not sound exactly the same as they do for a person with normal hearing. The benefits from a cochlear implant may vary for different people. Some of the benefits are as follows:
- Improved potential for young children to develop spoken language.
- Improved ability to understand speech when used with lip-reading.
- Increased awareness and recognition of environmental sounds.
- May be able to make telephone calls, especially with people they are familiar with.
- May be able to watch TV programmes more easily, especially when they can also see the speaker’s face.
What is involved in the cochlear implant process?
- Pre-operative evaluation
Our team of professionals will conduct several assessments to determine if a person is suitable for a cochlear implant. The ENT surgeon will order a scan of the ear as well.
- Surgery
Surgery is performed at Singapore General Hospital. The procedure, which lasts for about two hours, requires general anesthesia. Medical follow-ups will be done with the ENT surgeon.
- MAPping sessions
The Audiologist will activate the implant usually about three weeks after surgery. Programming of the implant, called MAPping, will be done to maximise speech sounds heard by the person. The initial session lasts two to three hours and subsequent sessions are scheduled at a two week interval for the next two months. Ongoing mapping sessions will be prescribed by the audiologist to optimise the cochlear implant function.
- Auditory-Verbal Therapy
Post-operative therapy is important for cochlear implant recipients to achieve the best results from listening through an implant. For children, therapy starts as soon as their cochlear implant has been activated.
What are the follow-ups required after surgery?
The implant has to be programmed by the audiologist before it can work. Programming of the implant will be carried out 2 to 3 weeks after surgery, after which the implant needs to be programmed periodically to maximize the speech sounds that can be heard by the individual.
A period of (re)habilitation is also required, especially in children, to gain the maximum benefits from listening through the implant. Implanted children will be enrolled in therapy sessions in Listen and Talk Programme, where the Auditory-Verbal approach is adopted to help children develop speech and language.
What should my expectations be?
A cochlear implant may not be the right choice for everyone. An evaluation by an experienced cochlear implant team will help you to decide.
No cochlear implant is able to restore normal hearing completely. However, with the cochlear Iimplant, adults can look forward to hearing sounds that may help them to carry on a conversation and participate in everyday life. The outcome in children varies, but the ultimate objective is that children can develop speech and language. For further information, please do not hesitate to contact us for an appointment.