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Cochlear Implant

Medical device that bypasses damaged structures in the inner ear and directly stimulates the auditory nerve.

PubMed Health Glossary
(Source: NIH - National Institute on Deafness and Other Communication Disorders)

About Cochlear 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. 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....Read more about Cochlear Implants National Institute on Deafness and Other Communication Disorders

What works? Research summarized

Evidence reviews

Effectiveness of Cochlear Implants in Adults with Sensorineural Hearing Loss [Internet]

Sensorineural hearing loss is the third leading cause of disability during the adult years, according to the World Health Organization. This type of hearing loss is usually permanent, most commonly occurs gradually, and becomes worse with increasing age with clinical manifestations typically appearing during the fifth and sixth decades. In recent years, cochlear implants have been used in adults with sensorineural hearing loss. Cochlear implants replace the function of hair cells that are no longer able to generate electrical impulses in response to sound. Therefore, these devices may provide a viable alternative to hearing aids among older adults with sensorineural hearing loss as they bypass damaged hair cells by directly transmitting the electrical impulses to the acoustic nerve. Currently, most patients are fitted unilaterally, with some receiving contralateral assistance with a hearing aid when residual low-frequency hearing exists. In recent years, the number of people implanted bilaterally has continued to increase. Therefore, the Centers for Medicare and Medicaid Services (CMS) is interested in an evaluation of recent published literature on the effectiveness of cochlear implantation. After consultation with the Agency for Healthcare Research and Quality (AHRQ) and CMS, this technology assessment has been commissioned specifically to evaluate the clinical effectiveness of unilateral cochlear implants and bilateral cochlear implants in adult patients (≥ 18 years of age) with sensorineural hearing loss. The key questions were formulated in consultation with CMS and AHRQ.

The effectiveness and cost-effectiveness of cochlear implants for severe to profound deafness in children and adults: a systematic review and economic model

To assess the clinical effectiveness and cost-effectiveness of cochlear implants for children and adults with severe to profound sensorineural hearing loss by answering the following questions: 1. For severely to profoundly deaf people (either using or not using hearing aids), is it effective and cost-effective to provide a first (i.e. unilateral) cochlear implant? 2. For severely to profoundly deaf people with a single cochlear implant (either unilateral or unilateral with a hearing aid), is it effective and cost-effective to provide a second (i.e. bilateral) cochlear implant?

Bilateral cochlear implantation in children and the impact of the inter-implant interval

OBJECTIVES/HYPOTHESIS: To determine the effectiveness of simultaneous versus sequential bilateral cochlear implantation on postoperative outcomes in children with bilateral deafness and to evaluate the impact of the inter-implant interval and age at second implantation on postoperative outcomes in children who already received their first cochlear implant.

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Summaries for consumers

Hearing loss and deafness: Overview

In Germany and other countries, it is routine practice to test the hearing of newborn babies, to be able to diagnose and treat hearing problems early on. This can help improve language development in hearing-impaired children.

Auditory‐verbal therapy for promoting spoken language development in children with permanent hearing impairments

Permanent hearing impairment greatly restricts a child's speech and language development and hinders his or her behavioural, cognitive and social functioning. Although technological devices, such as hearing aids and cochlear implants, enable the child to hear spoken words, they fail to teach the child how to listen, how to process language or how to talk.

Hearing loss and deafness: Hearing tests in newborns

In Germany and other countries, newborn babies are routinely given hearing tests in order to detect and treat hearing impairments as early as possible. This can improve early language development in children who have hearing problems.Nearly all babies can hear well: 997 out of 1,000 babies are born with normal hearing. Up to 3 out of 1,000 newborns have a moderate or severe hearing impairment. Although these children hear a little worse than normal, most of them are not deaf. Without early hearing tests, hearing problems are often first detected when a child is between two and four years old. But hearing tests in newborns cannot detect hearing impairments in all children because some hearing impairments only develop later on in childhood.

Terms to know

Auditory Nerve (Cochlea Nerve)
Connects the inner ear to the brainstem and is responsible for hearing and balance.
Snail-shaped structure in the inner ear that contains the organ of hearing.
The inability to hear in one or both ears.
A sense organ needed for the detection of sound and for establishing balance.
The perception of sound by the ear.
Hearing Aids
Electronic device that brings amplified sound to the ear. A hearing aid usually consists of a microphone, amplifier, and receiver.
Sensorineural Hearing Loss
Hearing loss caused by damage to the sensory cells and/or nerve fibers of the inner ear.

More about Cochlear Implant

Photo of an adult woman

Also called: Artificial cochlear implant, Cochlear prosthesis, CI

Other terms to know: See all 7
Auditory Nerve (Cochlea Nerve), Cochlea, Deafness

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