Cochlear implants are sophisticated medical devices that provide individuals with severe to profound hearing loss (who derive limited benefit from hearing aids) with meaningful access to sound. While hearing aids amplify sound, cochlear implants bypass damaged portions of the inner ear and stimulate the auditory nerve directly. Cochlear implants have two primary components: (1) a surgically implanted receiver with an electrode array and (2) an external sound processor which can be worn on the ear or the head behind the ear.

Cochlear Implant External Components

The cochlear implant’s outermost component is an attached microphone, which picks up sound waves. This information is transmitted to a sound processor that converts the signal into electrical impulses.

The sound processor analyzes and refines the incoming sounds, then separates high from low pitches, adjusts the volume to facilitate comprehension, and converts the sounds into a digital code. A transmitter wirelessly sends the processed signal to the internal cochlear implant components, prepping the sound information for the inner ear.

Cochlear Implant Internal Components

The internal components of the cochlear implant are a receiver and an electrode array. The former, implanted under the skin behind the ear, receives the digitally coded message from the external component and translates it back into electrical pulses. 

The electrode array (a thin wire) is placed by the CI surgeon in the cochlea. Multiple electrodes correspond to various sound frequencies. Electrical pulses from the receiver travel down the electrode array and stimulate the auditory nerve.

Interpreting Sound with a Cochlear Implant

Once the electrical pulses reach the auditory nerve, the brain interprets them as meaningful sounds. This process effectively mimics natural hearing, though the sound quality perceived through a cochlear implant may differ from typical hearing.

Over time and with practice, the brain rewires itself to interpret the patterns of electrical pulses. For example, high-frequency sounds typically stimulate electrodes near the base of the auditory nerve, while low frequencies activate those closer to the tip. The brain learns how to associate electrical patterns with sounds and speech features, allowing individuals to understand speech and discern music and other environmental sounds. Adults and especially children derive listening improvements from practice and formal auditory (re)habilitation.

Contact ACI Alliance Today

New technology continues to enhance cochlear implants’ functionality, making them an increasingly effective solution for individuals with hearing loss. Learn more about your cochlear implant options by contacting ACI Alliance today.