Every 25th February is celebrated all over the world as International Cochlear Implant Day to raise awareness on cochlear implant. Hearing ability is integral for children to develop speech and language skills as they grow up. Previously, hearing loss in children often went undetected until the child was around two years old, when it became obvious that he or she wasn’t talking yet. Nowadays, awareness in this regard has increased by leaps and bounds.
According to WHO around 466 million people worldwide have disabling hearing loss and 34 million of these are children. A recent study by The Indian Journal of Medical Sciences states that around 7% of the population of India suffers from profound deafness and more than a million children needs either hearing aid or cochlear implant surgery to restore their hearing power. Many of them had never heard a single word since their birth and still only 5000 cochlear implant surgery has been conducted in the country. The main reason of such poor penetration of the surgery is the lack of trained man-power to conduct such surgeries.
There is no denying the fact that a child has to be diagnosed for hearing loss at the earliest. Nowadays, tests can be done on a one-day-old baby by using an universal screening method using an OAE (Oto Acoustic Emission), which is a low-level sound that is emitted by the cochlea triggered by an auditory stimulus. These sounds can be used to test the function of the cochlea and understand the level of the damage in the hair cells function and other parts of the ear, including the auditory nerve.
According to Padmashree awardee Prof. (Dr) J. M. Hans of Rainbow Children’s Hospital, who has done more than 3000 cochlear implants surgeries,” If a baby fails in an OAE test, a Brainstem Evoked Response Audiometry (BERA) test needs to be done. A healthy hearing nerve transmits nerve impulses at a particular speed from the inner ear to the brainstem. The BERA test determines the rate at which the nerve impulse travels and indicates the occurrence of hearing loss. This will indicate the level of hearing loss. However mild hearing loss may not be detected by the test.“
The primary task after diagnosis is to put the child on hearing aid. The target is to keep the auditory nerves active till a Cochlear implantation is done. One must remember that the cochlear implant has to be done at the age of eight months if there is no response with hearing aids on both ears. Added to that, a meticulous speech therapy is required for the child to understand what the child is hearing and to initiate speaking. In some cases, the speech therapy may go on for more than a year at times even if the cochlear implant has been done as early as eight months.
Prof. (Dr) J. M. Hans further added,”The need for cochlear implant in this country is enormous as we have about 40 Lac children who are in need for cochlear implants. In my 20 years of experience in the field of Cochlear Implantations I have performed only 3000 implantations. This clearly shows the lack of awareness on Cochlear implantations. Don’t forget that the best results with a cochlear implant can be observed if the implantations are done between eight months and 2 years of age as 80 percent of the brain develops during this period of life. The results of the Cochlear implants done within the age of five will also be good but the child will require a lot of speech therapy. For children between the age of five and ten, Cochlear implantation may help them in hearing and understanding but it will affect their speech. And in children above the age of ten, Cochlear implantations will only help them in hearing. They will also be able to understand things to an extent but will not be able to speak at all.”
The message is quite clear – early detection and early treatment will give best results with regards to Cochlear implantation.