FinleyNotes
Charles Finley from BME
Charles Finley gave a presentation on Cochlear Implants, their history, and their future.
The first implant was introduced in the late 1950’s, with the technology such that a wire would connect through the skin of the patient. The quality of sound was also very much distorted, to the point that users could really only use the device to understand that a sound was happening, rather than for understanding the sound. At this point, the device was using one channel for sound.
The jump from 1 to 4 channels brought a vast improvement in the results. The channels are also varied (non simultaneous) to keep interference of signal to a minimum. Patience understood speech much better. Current technology now incorporates 16–20 channels.
The device has 3 parts externally: the processor, the microphone, and the transmitter and 2 parts internally, a receiver and an electrode.
The processor works to break the sound into different varying channels, and omit background noise. The microphone picks up the sound for the processor. The transmitter transmits the sound from the hearing piece through the skin, to the receiver. The receiver picks up the transmission just under the skin, and passes the transmission to the electrode, which works to stimulate the nerve endings within the cochlea.
The cochlear implant works by playing ‘chopsticks’ on the cells in your inner-ear, which in tern simulate speech.
There are 2 forms of deafness [the device can be helpful for severe cases of both]- Conductive: defect in the mechanical transfer [in the inner-ear]
- Sensory neural: morphing of the cells which trigger nerves
- If by age 3 the device is not implanted, the results begin to suffer, as the brain does not develop the ability to process sound.
