The ability to hear is something many of us take it for granted. Some people listen to their favorite music at maximum volume, never taking precautions when sound levels are louder than a simple conversation. From the moment we start to explore the world when we are just babies, we listen and organize each sound in our memory banks. Thereafter, we start to comprehend language and acquire the ability to communicate with others with speech. But what happens to those children that are born deaf due to genetics or adults that loose their hearing due to a disease or an accident? For many decades, these individuals had no hope on ever having the ability to hear the world or regain the sense of hearing. The medical field gave no hope on restoring it either. It was thought that sound had to travel through the ear canal, middle ear, and then to the cochlea in order to ever gain that ability. This idea was then challenged when it was discovered that the auditory nerve (cochlear nerve) translated electrical impulses into sound. This theory was then confirmed, from that point and on led to research and development, trials, and ultimately FDA approved implants.
In the normal ear, sound waves travel through the ear canal and vibrate the tympanic membrane, which in turn vibrate the ossicles, and then the vibrations are transferred from stapes to the oval window to the cochlea. In the Cochlea is where the vibrations stimulate hair cells and electrical impulses travel the cochlear nerve. The brain then translates these into what we know as sound. In contrast, someone who is deaf, the sound waves are not conducted well in the outer and middle ear, therefore poor vibrations do not reach the cochlea. Others may have cochlea damage and a cochlea implant is the best way to restore hearing loss. .
In the late 18th century Alessandro Volta, the inventor of the first battery, discovered that the auditory system could be electrically stimulated to create a perception of sound.