| Cochlear Implant |
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A cochlear implant (CI) is a surgically implanted electronic device that provides a
sensation of sound in a person who is profoundly deaf or severely hard of hearing. This is the first truly bionic implant that gets integrated with the body’s neural system. Thus, it is also called as Bionic ear. Unlike hearing aids, the cochlear implant does not amplify sound, but works by directly stimulating any functioning auditory nerves inside the cochlea with an electric field.
External components of the cochlear implant include a microphone, speech processor and an RF transmitter. The internal components that include the RF receiver is implanted beneath the skull's skin and an electrode array. The transmitter is coupled magnetically to the receiver.
After the implant is put into place sound will be picked up by a microphone and sent through the device's speech processor to the implant's electrodes inside the cochlea. The presence of auditory nerve fibres is essential to the functioning of the device: if these are damaged to such an extent that they cannot receive electrical stimuli, the implant will not work.
Post-lingually deaf adults and pre-lingually deaf children form two distinct groups of potential users of cochlear implants with different needs and outcomes.The risk of surgery in the older patient must be weighed against the improvement in quality of life. Research shows that congenitally deaf children who receive cochlear implants at a young age (less than 2 years) have better success with them than congenitally deaf children who first receive the implants at a later age, though the critical period for utilizing auditory information does not close completely until adolescence. It has been estimated in 2002 that around 10,000 children in the US and an additional 49,000 people worldwide have received Cochlear implants. By the end of 2007, the total number of cochlear implant recipients has grown to an estimated 120,000 worldwide.[6]
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