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July 14, 2004

Deaf Need Not Despair, Cochlear Implant Is Here

From: Star of Mysore, India - Jul 14, 2004

Mysore, July 14 (BRS)- Conductive hearing loss due to obstruction of or perforation of the ear drum, infection of the middle ear (ear canal), sensory-neural hearing loss and aging are the important causes of deafness of varying degrees and nature mild, moderate, severe or profound. Approximately, 1 out of 12 persons in India experience hearing problems. Cochlear Implant, a new device surgically implanted in the inner ear, can almost restore the hearing ability to the deaf, explained Dr. Sneha V. Bharadwaj, a Specialist in Speech and Hearing from the Texas University, USA.

She was delivering a talk on 'Cochlear Implant Surgery for overcoming hearing impairments' under the auspices of the Institution of Engineers (IE) in S.P. Bhat Hall of IE on Monday.

The Implant

The device Cochlear Implant consists of a microphone, speech processor, transmitter, receiver and an electrode array placed surgically in the inner ear. In essence, the entire hearing mechanism the ear is bypassed connecting the auditory nerve in the inner ear directly.

Speech heard with the help of the implant is not like the real one but is understandable, Dr. Bharadwaj said. Only those with profound hearing loss (inability to hear sounds of 90 deciBells dB or more) can benefit from the implant, she explained.

In children

Genetic factors, viruses, infections such as herpes and ad- ministering Ototoxic (poisonous to the ear) drugs during pregnancy are the main causes of deafness that happens before birth of the child.

Meningitis, measles, head injury, ear infections not treated in time, exposure to loud noise are the important causes of deafness in children.

Warning signs

The levels of sound vary on a measurable scale: Conversation 60 dB, vehicular traffic 90 dB, moving trucks 100 dB, car horns 110 dB, Concerts 120 dB, fire crackers 130 dB. The threshold level for bearing the impact of sound by the human ear is put at 140 dB, at which level one experiences pain in the ear, Dr. Bharadwaj observed.

The early warning signs before hearing loss are: Ringing in the ear, feeling like presence of cotton inside the ear and problems of sleeping as well as concentration. Exposure to 80 dB level of sound for long periods 8 hours such as in case of the traffic Policeman, 98 dB for 4 hours, 100 dB for 2 hours, 105 for 1 hour and at levels more than 120 dB for a short while can result in premature hearing loss.

Keeping distance from the sources of sound at hurting levels The Two-Metre Rule, avoiding nearness to loud music and noisy machinery and creating no-horn zone are important measures to prevent deafness. Using ear plugs made of foam and taking a 15-minute quiet-break frequently are other measures.

What to do ?

Avoid Ototoxic drugs such as some antibiotics, chemotherapy agents, anti-malarial drugs and aspirin compounds to prevent hearing loss. It is best to consult an ENT Specialist and also get the hearing evaluation at the All India Institute of Speech of Hearing, Mysore, where an audiogram is recorded for determining the status of the hearing ability.

Hearing aids, selected with the advice of a specialist, FM (Frequency Modulator) systems, telephone amplifying systems are of much help in overcoming hearing loss. Of course, Cochlear Implant is more beneficial than all these.

The surgery

Cochlear Implant Surgery takes between two and three hours and upto six weeks before hearing loss is overcome to the extent possible.

The device is programmed to suit specific beneficiary. It does not completely restore the normal hearing ability. It is best to implant children very early say, before 3 years of age. Babies of 6 to 7 months have received the implant with much benefit.

Benefits and Risks

The Cochlear Implant improves voice quality. It helps in detection of environmental sounds. Understanding speech without lip-reading is rendered possible by the implant.

Adverse effect of general anaesthesia; inflammation or infection following surgery; disturbance to facial nerve, sense of taste and balance; stiffness or numbness around the ear; dizziness; and even failure of the device (nearly 3 per cent) are some important risks associated with Cochlear Implant Surgery, Dr. Bharadwaj observed.

Persons with the Implant cannot be exposed to magnetic field and, therefore, will not be able to undergo Magnetic Resonance Imaging (MRI) procedure, she added.

Dr. A.P.J. Abdul Kalam, President of India, has urged creation of indigenous Cochlear Implant manufacturing capabilities in India aimed at bringing down the cost of CI surgery, now estimated at Rs. 5 to Rs. 10 lakh for the device and additional Rs. 50,000 for the surgery, Dr. Sneha Bharadwaj explained.

Mr. P.J. Bharadwaj, a senior Corporate member of IE, Mysore, presided. Mr. K.B. Bhaskar, Hon. Secretary, welcomed. Mr. N.B. Srimanth Kumar, Joint Secretary, proposed a vote of thanks.

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