COCHLEAR IMPLANT

A cochlear implant is a tiny, sophisticated electrical device that helps people who are profoundly deaf or extremely hard of hearing.

A hearing aid and a cochlear implant are not the same thing. Hearing aids enhance sounds so that deaf ears may hear them. Cochlear implants stimulate the auditory nerve directly, avoiding damaged parts of the ear. The auditory nerve carries the signals produced by the implant to the brain, which interprets them as sound. Hearing through a cochlear implant is different from normal hearing and takes time to learn or relearn. However, it allows many people to recognize warning signals, understand other sounds in the environment, and understand speech in person or over the telephone.

Children and adults who are deaf or severely hard-of-hearing can be fitted for cochlear implants. As of December 2019, approximately 736,900 registered devices have been implanted worldwide.

Around 7% of the population of India suffers from profound deafness. More than a million children needs either hearing aid or cochlear implant surgery to restore their hearing. Many of them had never heard a single word since their birth. Still only 5000 cochlear implant surgery has been conducted in the country. 

The FDA first approved cochlear implants in the mid-1980s to treat hearing loss in adults. Since 2020, cochlear implants have been FDA approved for use in eligible children beginning at 9 months of age.

Cochlear Implant Candidacy Criteria

Adults

• Individuals 18 years of age or older

• Moderate to profound sensorineural 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 binaurally1 

Children (2-17 Years)

• Severe to profound sensorineural hearing loss in both ears

• Limited benefit from binaural amplification

• Multisyllabic Lexical Neighborhood Test (MLNT) or Lexical Neighborhood Test (LNT) scores ≤ 30%

Children (9-24 Months)

• Profound sensorineural hearing loss in both ears

• Limited benefit from binaural amplification

  
  

  

  
  
  
  

  A cochlear implant system consists of internal and external components.

   The internal system is surgically implanted inside the auditory system while the external system is worn behind the ear, in a pocket, in a belt pouch, or with a harness.

   The external system consists of a microphone, a speech processor, a transmitter, and a magnet. Its role is to capture the sounds from the environment, to process them, transforming the auditory signals in electrical signals and to transmit them to the internal part.

  The internal system consists of a receiver, stimulator, electrode system, and magnet. Its role is to receive the electrical signals from the outer part and to transmit them to the auditory nerve fibers in the cochlea.

  Binaural hearing: -

  It is only when you hear with two ears that your brain is able to fully understand sound. If you can only hear in one ear (unilateral hearing) it may be difficult to Understand speech in noise, locate sound and avoid the head shadow effect.

  Bimodal hearing (hearing aid and hearing implant): -

  Bimodal hearing combines the benefits of a hearing aid in one ear and a hearing implant in the other ear. The result is a richer and more natural hearing experience.

   With a bimodal hearing solution, you may experience many benefits, including:

  • Clearer sound and improved speech understanding, especially in noise

  •  Being able to better tell where sounds are coming from

  • Being able to enjoy music more.

  If you have a bimodal solution but still struggle to understand speech, bilateral hearing implants may be the answer to help you communicate effectively.