Cochlear Implants

Singapore General Hospital started cochlear implant services since 1998. It is one of the many specialised programmes 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 rehabilitative care.

The Centre has seen more than 500 patients (adults and children) successfully implanted with the device. 

Patients under this programme are referred to our Auditory Verbal Therapy for therapy sessions.

To download our English cochlear implant brochure, please click here.
To download our Chinese cochlear implant brochure, please click here.

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:

1. 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).
   
2. The transmitting coil (B), sends the codes across the skin to the receiver/stimulator.
   
3. 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 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.
4. 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. 

What are the potential benefits from 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.