Cochlear Implant Surgery

Division of Otology, Neurotology, and Skull Base Surgery

The Douglas Grant Cochlear Implant Center evaluates and treats adults and children who receive inadequate benefit from hearing aids. UCSF has been an international leader in the development and application of electrical stimulation of the auditory system to restore hearing for more than 35 years. The Cochlear Implant Team provides the most advanced technology and service to patients, including Hybrid Implants (combined electrical and acoustical hearing).

Implant Process

How It Works

A cochlear implant is an implantable electronic device that provides useful sound perception via electrical stimulation of the auditory nerve. UCSF offers three cochlear implant systems manufactured by Advanced Bionics, Cochlear Corp. and Med-El Corporation. The Implant System has three parts:

  1. Implantable stimulator. The implantable stimulator consists of an electrode array and other electronic components. The electrode array is inserted into the cochlea to provide direct electrical stimulation to the auditory nerve. The electronic components are housed in a bio-compatible case which is surgically implanted under the skin and behind the ear selected for implantation. A magnet inside the case couples to the magnet in the headpiece.
  2. Headpiece / Transmitter. The headpiece and transmitter are worn externally on the head, and sit over the internal portion. The transmitter magnetically couples to the implanted stimulator. The microphone picks up sound in the environment and the transmission system sends the custom-coded signal across the skin to the implantable stimulator and electrode array. Electrical current is then sent to the auditory nerve which in turn sends signals to the brain where they are interpreted as sound.
  3. Speech processor. The speech processor is worn externally on the ear or the body. The speech processor converts sound into a distinctive code. This code is transmitted through the headpiece/coil across the skin via radio waves to the implantable stimulator.Welcome to the UCSF Cochlear Implant Center. Cochlear implants are designed to provide useful hearing to adults and children with significant hearing loss who are unable to receive benefit from hearing aids. A cochlear implant is an implantable electronic device that provides useful sound perception via electrical stimulation of the auditory nerve. It consists of the internal (surgically implanted) implantable stimulator and external (worn on the ear/body) headpiece/transmitter and speech processor.


Criteria For Adults

  • 18 years of age or older
  • Severe to profound hearing loss in both ears (70 dBHL or greater)
  • Limited benefit from hearing aids
  • Desire to improve hearing and realistic expectations
  • Cannot understand most phone conversations
  • Comprehension of TV primarily with use of closed captions
  • No medical contraindications
  • Rely heavily on lip reading
  • Limited social, educational or professional life options

No medical contraindications

A Cochlear Implant May Help You If You

  • Cannot understand most phone conversations
  • Need closed captions when watching TV
  • Rely heavily on lip reading
  • Have limited social, educational or professional life
  • Desire to improve hearing
  • Have no medical contraindications

Criteria For Children

  • 12 to 23 months of age with profound hearing loss in both ears (90 dBHL or greater)
  • 24 months to 17 years of age with severe to profound hearing loss in both ears (70 dBHL or greater)
  • A general lack or plateau of auditory development
  • Motivation to improve hearing and realistic expectations by the family
  • Little or no benefit from appropriately fitted hearing aids
  • No medical contraindications
  • Appropriate educational placement for school-aged children

A Cochlear Implant May Help Your Child If He/She

  • Has delayed or lack of speech and language development
  • Rarely responds to name
  • Does not alert consistently to environmental sounds
  • Lack of social interaction with children and adults
  • Is enrolled in educational program and/or therapy emphasizing speech, language and auditionA Cochlear Implant May Help You If You

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Candidates must meet specific criteria in order to receive a cochlear implant. The candidate is evaluated on an out-patient basis over a one-to-two day period at UCSF. Patients are selected for implantation based on medical and audiological histories and test results, findings and recommendations of the psychological interview, educational placement, family support and therapy services available for the pediatric candidate. Cochlear implantation is covered by most health insurance providers including Medicare and Medi-Cal. Please click here if you would like to be evaluated for a cochlear implant

Due to the number of procedures, the evaluation generally takes more than one day to complete. In addition to the formal test measures, considerable time is spent discussing the components of the device and their function, the surgical process as well as the benefits and limitations of a cochlear implant. The evaluation process differs slightly between adults and children.

Components of the evaluation:

1. Medical Evaluation
Conducted by the implant surgeon who will take a medical history, examine the ears, review CT and MRI images and explain the surgical process. All implant surgeons are in the Department of Otolaryngology at UCSF.

2. CT Scan and MRI
Completed in the Department of Radiology. These images produce important pictures of the inner ear that allow the surgeon to evaluate the ear's internal structure, recommend which ear to implant and may provide information as to the cause of deafness.

3. Audiological Evaluation
Consists of: a hearing test to confirm type and degree of hearing loss, a hearing aid evaluation to assess benefit provided by hearing aids, and aided speech recognition testing to determine whether a hearing aid provides greater benefit than that anticipated with the implant.

4. Psychological Screening
A psychological screening is recommended to assess the candidate's feelings about hearing loss, the cochlear implant, reasons for seeking the implant and to evaluate expectations about the cochlear implant.

5. Cochlear Implant Counseling/Orientation Session
The purpose is to review and discuss the components of the device, the possible benefits and limitations of implantation and recommend in favor of or against implantation based upon the results of the entire evaluation.

6. Listening Therapy Evaluation (Aural Rehabilitation)
Provided by a Speech and Language Pathologist with special knowledge in the area of Aural Rehabilitation at Hearing and Speech Center of Northern California. The purposes are to establish your baseline listening skills using your hearing aids before receiving a cochlear implant, to explain what post-implant aural rehabilitation (listening therapy) is about and to discuss the role of aural rehabilitation in helping you maximize your listening skills.

Programming and Testing

Device Programming. After the healing period, the patient returns to the Cochlear Implant Center at UCSF to have the externally worn speech processor programmed. The speech processor converts speech into a special code for each user. Each program is customized for the user.

Testing. Implanted patients are requested to return to the Cochlear Implant Center at UCSF at regular intervals for device checks and re-evaluation. During these visits, the implant and equipment are checked and performance is measured. Re-testing generally occurs at 1, 3, 6 and 12 months following the initial device fitting. Thereafter, semi-annual or annual evaluations are requested.

Surgery and Healing

Before Surgery. All of your questions regarding surgery will be answered by your surgeon during your initial medical evaluation. The implant team encourages you to meet with or contact your surgeon again at any time prior to surgery for any further questions or concerns. The UCSF Prepare Program is designed to prepare the patient for surgery. During these appointments, the patient meets the anesthesiologist, hospital admitting personnel and undergoes any additional medical tests felt to be needed. You may also be required to have a clearance from your primary care physician.

The Surgical Procedure. On the morning of surgery, it is important to arrive on time, and have a contact phone number available to the staff in the event you need to be contacted if the surgery time changes. Be sure to refrain from all food or drink the morning of surgery. If you eat or drink anything within 6 hours of your surgery, your operation could be delayed or cancelled.

A cochlear implantation surgery takes approximately 2-3 hours in most cases. A very small amount of hair is shaved from behind the ear, which is usually not noticeable when the hair is let down. An incision is then made behind the ear, and a pocket is created to allow the receiver-stimulator to sit unobtrusively under the skin and firmly anchored to the skull. A mastoidectomy is then performed, which entails removing the bony septations in the mastoid with a high speed surgical drill and a microscope. This is a very standard ear operation. After some important structures are identified to provide landmarks (such as the incus bone, one of the balance canals), a small opening is made into the middle ear, to provide access to the cochlea. A small hole is then made into the cochlea (the ‘cochleostomy’) to allow insertion of the implant electrode. The implant is then secured to the bone in the pocket previously created, and the electrode gently inserted into the cochlea. The wound is then closed and a mastoid dressing is placed. The patient is generally in recover for 2 hours, and then sent home on the same day. For patients with underlying medical conditions, an overnight stay in the hospital may be recommended.

Possible Complications During or After Surgery. Though the surgery is ordinarily quite safe, there are known, but rare complications that can develop. The most commonly reported complications occur with the skin behind the ear over the implant receiver, which can occasionally break down, leading to an exposed implant. Changes in the way food tastes, due to injury of a nerve in the middle ear, can temporarily occur in approximately 1 in 8 of cases. Rarely this change of taste will be permanent. Injury to the nerve controlling the facial muscles is very rare (<1 in 1000 cases), but if it were to occur, could leave the patient with a permanent weakness of the facial musculature. Other rare complications include leakage of brain fluid (~1%). Approximately 2-3% of patients will require their implant to be removed due to device malfunction or infection. However, in nearly all these cases a new implant can be placed without further difficulty. If the risks of any of these complications are unacceptable to you, you absolutely must discuss this with the surgeon prior to surgery.

Healing and Post-operative Care. Following surgery, the patient returns home. The mastoid dressing is removed by the patient or family member 2 days following surgery. The wound is cared for by cleaning it twice daily with hydrogen peroxide (mixed 50/50 with distilled water), carefully and gently cleaning off the edges of the incision to keep it clean, followed by application of any over-the-counter antibiotic ointment (eg Bacitracin). If there is tape overlying the incision, then one needs just to keep the area dry for 3 days without the need for wound cleaning. The patient may shower and wash their hair 3 days following surgery. You will have a post-operative visit approximately 2 weeks after your surgery, that will primarily consist of a wound check and ear exam. No sutures will have to be removed since they are dissolveable.

When to Call your Doctor Following Surgery. In most cases, there are no problems following surgery. After removal of the dressing, you or a family member or friend should examine the incision. You should notify your surgeon or the clinic staff if the following is noted:

The wound looks red and swollen and doesn’t improve over the next 1-2 days, and is painful to touch.
Fevers >101.5 deg
Swelling of the skin behind the ear or the feeling of fluid accumulating underneath the skin behind the ear.
Headaches, light-sensitivity or excessive lethargy following surgery.
Any questions regarding wound care, or medical concerns about yourself or your child.

Emergency contact numbers:

For routine clinic questions or questions for your surgeon, you may leave a message on the nursing line at 415-353-2148.

You should get a call back within 12 hours; if not, please call and leave another message.

For an emergency, you may reach the physician on call by contacting the hospital operator at 415-476-1000 and asking to speak to the Otolaryngology resident on call.



Will a cochlear implant restore normal hearing for persons who are deaf?

A cochlear implant does not restore normal hearing. It is a communication tool but not a "cure" for deafness. Cochlear implants can provide more access to speech information than previously received from a hearing aid. Practice with the implant, supplemented with listening therapy are effective means to obtain the maximum benefit from this device.

Is cochlear implant surgery risky or dangerous?

Risk is inherent in any surgery requiring general anesthesia. However, the surgical risks for cochlear implantation are minimal and the majority of patients require only a one-day hospital stay and have no surgical complications.
Will additional surgeries be needed to take advantage of improvements in technology as they become available?

The surgically implanted unit is designed to last a lifetime. The externally worn speech processor, which is responsible for coding the speech and sending the information to the internal unit, is software-dependent and can readily accept new and improved speech-coding technology as it becomes available. Additionally, the speech processor may be upgraded as technology improves.

Do children outgrow the internal device requiring an additional surgery after their bodies grow?

The cochlea is fully formed at birth and the skull structures have achieved almost full growth by the age of two. The electrode array is designed to accommodate the skull growth in children.

Is it better to wait for new technology to become available before getting a cochlear implant?

The design of the surgically implanted receiver and electrode array has changed relatively little during the history of cochlear implants. In contrast, the speech coding strategies, which are responsible for delivering the signal to the internal unit and are stored in the externally worn speech processor, have changed significantly in recent history. The speech processor is designed to accept new strategies when available. It is always best to receive your cochlear implant sooner rather than later as there is a learning curve associated with the device, and duration of deafness can have a profound impact on the patient's performance over time.

Is it better to wait for new technology to become available before getting a cochlear implant?

The design of the surgically implanted receiver and electrode array has changed relatively little during the history of cochlear implants. In contrast, the speech coding strategies, which are responsible for delivering the signal to the internal unit and are stored in the externally worn speech processor, have changed significantly in recent history. The speech processor is designed to accept new strategies when available. It is always best to receive your cochlear implant sooner rather than later as there is a learning curve associated with the device, and duration of deafness can have a profound impact on the patient's performance over time.

Is it true that Implant users can only identify environmental noises, not speech?

Cochlear implants provide a wide range of sound information and performance on speech perception testing does vary among individuals; however, with time and appropriate rehabilitation, most users understand more speech than they did with their hearing aids and many are able to communicate by regular telephone or enjoy music!

Can implant users swim, shower, or participate in sports?

When NOT wearing the external equipment, users can swim, shower, and participate in any number of water activities. The only restriction placed on implant users relates to skydiving and scuba diving as the significant air-pressure changes encountered in these activities is not advisable. Participation in all other athletic pursuits is unrestricted though protective head gear is always wise.

Are cochlear implants considered new and experimental?

Cochlear implants have been around since the 1970's and several devices are currently FDA-approved for use in children and adults.

How much benefit will a cochlear implant provide?

The degree of benefit from a cochlear implant, including speech comprehension and music appreciation, varies from person to person. Your cochlear implant team will counsel you on how your length of hearing loss, experience with hearing aids, cause of hearing loss and other relevant factors affect your prognosis. However, motivation, realistic expectations and following through with recommendations will have a positive effect on the progress and benefit you receive.

Will I/my child hear and understand speech right away with a cochlear implant?

A cochlear implant does not sound like “normal” hearing. Although most people will detect sounds right away with the cochlear implant, it will take time for someone who lost their hearing to make sense out of the new sounds and speech heard with a cochlear implant. Likewise, for a child born with significant hearing loss, time will be needed to learn sounds and speech and to begin to talk. Using the device all waking hours, keeping all appointments and engaging in listening therapy (aural rehabilitation) will promote progress with the cochlear implant.


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Trouble Shooting

On occasion, you may experience problems with your cochlear implant. All patients implanted at UCSF are provided with two processors meaning there is a back up to use to keep you hearing when one processor is not functioning. The steps below should be followed in the order given to quickly identify the problem and get your device working properly again.

  1. Follow troubleshooting steps found in your owner’s manual or click on your device manufacturer’s name below to be taken to an online troubleshooting guide:

2. Contact customer service for your manufacturer for additional help troubleshooting if needed or to order parts to replace defective components.

  • Advanced Bionics 877-829-0026
  • Cochlear Americas 800-523-5798
  • Med-El Corporation 877-633-3524

3. Contact UCSF Cochlear Implant Center at (415) 353-2464, if you are unable to receive the help needed by following steps 1 and 2 above.