It is an electronic device placed under the skin by the doctors which carries sound, bypassing the damaged parts of the ear, to stimulate hearing nerve, which in turn carry those signals to brain for understanding.

Parts of Cochlear Implants:

  • 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 signals.
  • An electrode array, which is a group of wires that collects the signals from the stimulator and sends them to different parts of hearing nerve.


Anyone who are suffering with severe to profound deafness, which means unable to hear sound stronger than 90 dB HL at a frequency of 2 – 4 kHz (a measuring unit of Intensity of sound). However, apart from assessing functional hearing ability a thorough assessment will be done by a multi-disciplinary team before surgery for the factors such as fitness for surgery and the ability of the person to derive benefit from cochlear implant system.

  • Individuals 18 years of age or older.
  • Moderate to profound hearing loss in both ears.
  • Limited benefit from amplification defined by preoperative test scores of ≤ 50% sentence recognition in the ear to be implanted and ≤60% in the opposite ear or binaurally.


  • Severe to profound hearing loss.
  • Limited benefit from binaural amplification.
  • Multisyllabic Lexical Neighborhood Test (MLNT) or Lexical Neighborhood Test (LNT) scores ≤ 30%.


The external components capture environmental sounds as well as speech and music.


They process these sound so they can be transmitted across the skin to the implant. The implant then passes the signals along to the electrode array.


The individual electrode then delivery these signals to the hearing nerve where they travel.

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4. Isaacson B, Lee KH, Kutz JW, Roland PS, Sargent EW. Cochlear Implants, Indications. emedicine medscape com.       Jun 25, 2010. Available at: URL: .