Thanks to advancements in technology, patients suffering from hearing loss (categorised as either profoundly deaf or severely hard-of-hearing) can once again hear the sounds of the world around them with a cochlear implant.
A cochlear implant differs to a hearing aid. A hearing aid is normally used to amplify sound to enable patients with damaged ears to hear things better. Cochlear implants bypass damaged portions of the ear and directly stimulate the auditory nerve.
Sound from the outside environment is transferred as waves through the outer ear to vibrate the eardrum. These sound vibration signals are transmitted to the ossicles bones in the middle ear which then transmit the vibration to the fluid-filled inner ear (cochlea). This motion creates movement in the fluid of the cochlea, stimulating its hair cells. The hair cells provide stimuli to the auditory nerve, which are then interpreted by the brain as sound.
Profound deafness or being severely hard-of-hearing is normally caused by damaged hair cells. A cochlear implant is a device that provides sound perception through direct electrical stimulation without touching these “hearing cells”.
According to the USA Food and Drug Administration (FDA), as of December 2012 approximately 324,200 people worldwide had cochlear implants. In the United States, roughly 58,000 adults and 38,000 children have received them. In Vietnam, only around 500 people have received this implant, even though the rate of congenital deafness in Vietnam is fairly high, i.e. up to four babies in every 1000.
According to Dr. Nguyen Quang Dai, Head of FVH’s ORL, a cochlear implant is a very effective treatment option for patients with hearing loss. Hearing is essential to young children as it helps help them to acquire speech, language and social skills; children as young as 12 months can be fitted for a cochlear implant.
The experience of hearing through a cochlear implant is different to normal hearing and takes time to learn or relearn. However, though practice, it allows many people to understand other sounds in the environment, and enjoy a conversation in person or by telephone.