How does a cochlear implant work and improve hearing?

Cochlear implants are neurostimulators that are inserted into the inner ear of deaf people. They bypass the damaged structures of hearing to directly to stimulate the auditory nerve with electricity producing a sensation of sound. After surgery, we wear an ear level processor that digitizes speech and delivers it wirelessly to the computer underneath the skin of the scalp. The electrodes curled inside our ears  deliver precisely arranged pulses to create a sensation of sound.

The vast, vast majority of patients with cochlear implants hear better with their implant than a hearing aid. However, the absolute hearing with the cochlear implant is unpredictable. This means that we can offer patients good assurance that they should benefit from a cochlear implant. We cannot predict if patients will receive a bit of benefit or become rock stars with their device.

Most patients who receive a cochlear implant are over 65 years old. These patients have gradually lost their hearing over time. Generally, this population of patients can expect to:

• hear better with their cochlear implant than a hearing aid 8 out of every 10 surgeries. The remaining patients may not do not improve. It is very rare for hearing to get worse with a cochlear implant. This occurs 1 out of every 100 cochlear implant surgeries.
• hear 65% (65 of 100 words) of single syllable words in quiet without lipreading.
• hear 80% of sentence content in quiet without lipreading.
• use the telephone conversationally 5 to 6 times out of 10 patients.