Cochlear Implant Mapping

Cochlear implants are small devices surgically implanted in the skull behind the ear, sending electrical signals to the auditory nerve. The brain learns to interpret these signals as sound.

The National Institute on Deafness and Other Communication Disorders (NIDCD) estimates that approximately 360,000 people in the United States have received cochlear implants as of 2018. The NIDCD also reports that more than 60% of children who receive cochlear implants can perceive some sounds after only one month of use.

Why do people get cochlear implants?

Although most people with hearing loss would do just fine with hearing aids, cochlear implants treat individuals with profound hearing loss or auditory deprivation who have not responded well to traditional hearing aids or other forms of treatment. People with hearing loss may benefit from cochlear implants because they offer better sound quality than traditional hearing aids for those with more acute hearing conditions. 

The downside is that cochlear implants involve a more invasive procedure than hearing aids, which involves inserting an implant into the head and connecting it to your cochlea.

The steps involved in installing a cochlear implant

1. The patient is evaluated by a team of professionals, including an audiologist, and a surgeon.
2. The patient's hearing ability is assessed, along with the level of hearing loss and any other medical issues that may affect the procedure.
3. A surgical plan is developed that considers the patient's age, general health status, and other factors such as prior surgeries and allergies to medications or anesthesia.
4. An incision is made behind the ear. The implant is inserted into the scala tympani (an opening in the inner ear) and attached to electrodes on either side of the cochlea (the part of the inner ear that converts sound signals into electrical impulses).
5. A speech processor is worn by the patient that picks up sounds from an external microphone. It processes these sounds to transmit them through an internal transmitter to electrodes placed in the cochlea. The sound then stimulates nerve cells in this area of the brain that can then send messages along the auditory nerve to the patient's brainstem, where they are interpreted as sound.
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Mapping and programming the cochlear implant

Following the surgery, the patient will see an audiologist like us for Mapping and programming.

Maps are programs that help the person with a cochlear implant get the best sound quality by adjusting the input to the electrodes on the array implanted in the cochlea. Even though each company that makes cochlear implants uses different terms, has different ways of programming, and has different amounts of space on their processors for different maps, the basic ideas behind mapping are the same for all three FDA-approved brands. 

For mapping, the cochlear implant processor is linked to the computer of the audiologist. The audiologist sets the T- and C- levels for each electrode by playing the user a series of "beeps" and observing how they react. The softest sounds that the users can hear are called T-Levels or Thresholds. C-Levels, also called M-Levels, are levels of volume that the CI user can handle. 

We may also change the map's stimulation rate or programming strategy. These computer algorithms and programs turn acoustic sound (what people with normal hearing hear) into the right combination of electrode stimulations to give the person with a cochlear implant the same feeling of sound.

Do you think you might be a candidate for cochlear implants? Contact us today to set up a consultation!