What Is a Bilateral Cochlear Implant?

A bilateral cochlear implant is an artificial hearing aid that is surgically implanted in a person who has significant hearing loss. The term “bilateral” means that both ears are implanted with a device, rather than just one ear. There is an external and an internal component to a cochlear implant. An external earpiece converts sounds to electrical currents and transmits them to the internal receiver. The current then reaches the auditory nerve, allowing the patient to “hear” the sounds.

People with cochlear implants cannot hear sounds the same way a person without hearing loss hears them. It takes time and practice to adjust to the new sounds. As the patient's brain becomes accustomed to the different sound signals, they should start to sound more natural. The bilateral cochlear implant does help people with hearing loss interpret lip reading more efficiently, as well as regulate their own voices.

Since the bilateral cochlear implant requires an adjustment in the perception of sounds, it is generally thought that young children are the most ideal candidates for the surgery as well as those who were not born with hearing loss. Despite this, adults who were born with hearing loss are not precluded from receiving the implants. Candidates for a bilateral cochlear implant do need to have active, undamaged auditory nerve fibers for the devices to work.

To prepare for the bilateral cochlear implant surgery, patients will meet with various specialists, including speech therapists, audiologists, and otologists, or ear doctors. Psychological counseling is also recommended to facilitate the transition. Patients will need to disclose their other medical conditions, as well as any medications and supplements they are taking.

Some people choose to have one ear implanted at a time, in two separate surgeries. This is called a sequential implantation, whereas in a simultaneous implantation, both ears are treated in the same session. A bilateral cochlear implant surgery will begin with administering general anesthesia so that the patient is not awake. The surgeon will make an incision and drill into the bone behind the ear. Part of the internal device is inserted into the cochlea portion of the ear, while the rest of it is implanted into the bone.

Patients should expect to return home the following day. They will meet with their audiologist about one month later to hook up the external devices to their ears. The external devices will be programmed and over the next few months, the patient may return to the audiologist to adjust the earpieces as needed. Following a bilateral cochlear implant, the patient will work with the audiologist and a speech therapist to improve his perceptions of sound.

There are a few risks associated with a bilateral cochlear implant. It may be possible that the surgery will destroy any residual hearing the patient has. This may interfere with the potential use of any future technologies and advancements for hearing loss. Some patients have also reported dizziness, nerve injuries, and infections or mechanical failures of the implanted device. The risks of any surgery can include adverse anesthesia reactions, infection, and bleeding.