This girl is one of approximately 219,000 people worldwide who have Cochlear implants. This device is an electronic device which provides a sense of sound to a person who severely hard of hearing. This device is also known as bionic ear. This device is also a surgically device via Wikipedia.
There is many versions of this device. The last one allow the patients to hear better in noise, enjoy music and they can also swimming while the implant turned on. The quality of sound is different from natural hearing, with less sound information being received and processed by the brain.
But there's an important note, This device is functional when the brain hear cells are not damaged, it's effected when only the hear cells sensory are damaged.
At this video you will see this 29 years old girl hearing her sound for the first time in her life and she was born deaf and she captured the time of testing the cochlear implant. This girl is called Sarah Churman and here is her blog http://sarahchurman.blogspot.com/.
