ear with cochlear implantCochlear Implants

A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. The implant consists of an external portion that sits behind the ear and a second portion that is surgically placed under the skin (see figure). An implant has the following parts:

  • A microphone, which picks up sound from the environment.
  • A speech processor, which selects and arranges sounds picked up by the microphone.
  • A transmitter and receiver/stimulator, which receive signals from the speech processor and convert them into electric impulses.
  • An electrode array, which is a group of electrodes that collects the impulses from the stimulator and sends them to different regions of the auditory nerve.

An implant does not restore normal hearing. Instead, it can give a deaf person a useful representation of sounds in the environment and help him or her to understand speech.

Other Implantable Devices

There are some types of conductive hearing losses that can be surgically corrected (e.g., fixing a hole in the eardrum or one of the middle ear bones) or improved with hearing aids. Other types of conductive hearing losses can be improved with implantable devices:

  • An implanted middle ear device
  • A surgically implanted, osseointegrated device (for example, the Baha or Ponto System)

Implantable middle ear hearing devices are designed to help increase the transmission of sound vibrations reaching the inner ear. Middle ear implants involve a small prosthesis attached to one of the bones of the middle ear. Rather than amplifying the sound traveling to the eardrum (as with a hearing aid), these prostheses help move the bones directly.

Osseointegrated devices are also treatment options for people with conductive or mixed hearing loss. These implants are surgically embedded to the outside of a person’s skull, behind the ear. A tiny titanium abutment is anchored to the skull to which an external processor is attached. When the microphone on the processor picks up incoming sounds, the processor transmits these sounds via the abutment to the inner ear through skull vibrations.