Cochlear Implants

Introduction

A cochlear implant is a small electronic device that can provide individuals, who have a severe to profound hearing loss, with a sense of sound. The implant does not restore normal hearing but it can give individuals the ability to understand speech. In many cases, cochlear implants have improved the quality of life for the individual. Researchers are continuing to improve the technology of cochlear implants to make the device available to all who could benefit from them.

Components of a Cochlear Implant


Cochlear Implants are composed of two parts, an implanted device under the skin, and an external device that is worn on the body. The external portion of the cochlear implant is made of the microphone, speech processor, and connecting cables. The internal device includes a coil and electrodes implanted within the skull and cochlea, respectively.

How Cochlear Implants Process Sound 

Speech, environmental sounds and music are picked up by a small, directional microphone located on the earpiece of the implant, which is positioned around the pinna. After the sound enters the microphone, it is sent to the speech processor through a small cord. The speech processor, usually worn on the belt, filters, analyzes, and digitizes the sound into a coded signal. The coded signal travels to the transmitting coil found on the individual’s head, behind the ear. The transmitting coil sends the signal to the internal coil located under the skin. Both coils are magnetized, keeping the transmitting coil in place. The cochlear implant transmits the signal from the internal coil to an electrode inserted in the cochlea that stimulates the auditory nerve. The auditory nerve sends the signal to the brain and the sound is processed. Even though the process seems long and complicated, the sound is transmitted in microseconds, allowing the individual to hear sounds instantaneously.