Hearing loss / Hearing impairment

This is How You Hear…

Sound waves enter into your ear and cause vibrations at eardrum. Three small bones present in the middle ear amplify these vibrations while they travel to the inner ear. In the inner ear (cochlea), the vibrations pass through the fluid of the cochlea. Tiny hairs attached to the nerve cells of cochlea help in translating the sound vibrations into electrical signals. The nerve cells transmit these electrical signals to the brain – where they turn into sound.

Hearing loss occurs commonly as you age. It is known as presbycusis – hearing impairment in old age. However, hearing impairment can occur at any age due to several reasons.

Hearing Loss: Global and Indian Statistics

According to WHO (2018) data, the prevalence of hearing impairment (HI) in India is around 6.3% (63 million people suffering from significant auditory loss) and 360 million people in the worldwide suffering from hearing impairment. 68.9% had a bilateral hearing loss while 31.1% had a unilateral hearing impairment.

In India, “hearing handicapped” as defined by The Rehabilitation Council of India Act, 199213, is – hearing impairment of 70dB and above, in the better ear or total loss of hearing in both ears.

The average lifetime cost for one person with hearing loss is approximately $420,000 this includes household and workplace productivity loss.

Causes of Hearing Loss

The major causes of hearing loss and ear diseases in India have been listed by the WHO survey and include the following:

• Excess ear wax (15.9%) was the most common cause of reversible hearing loss.
• Non-infectious causes such as ageing and presbycusis are the next most common (10.3%).
• Middle ear infections such as CSOM (5.2%) and serous otitis media (3%)
• The other causes include dry perforation of the tympanic membrane (0.5%)

Bilateral genetic and congenital deafness (0.2%). Approximately 50% of all cases of congenital hearing Impairment are attributable to environmental factors, such as congenital hyperbilirubinemia, ototoxic medication exposure, neonatal hypoxia, viral infections and meningitis. The other 50% of cases are thought to be inherited, i.e., of genetic causes.

Other Causes

• Damage to the inner ear – due to loud noises, wear and tear and ageing.
• The gradual build-up of earwax
• Abnormal bone growth or tumours
• Ear infections – middle and inner ear infections
• Ruptured eardrum

Hearing Loss Types

Conductive Hearing Loss (involves outer or middle ear)

Hearing lmpairment caused by something that stops sounds from getting through the outer or middle ear. This type of hearing loss can often be treated with medicine or surgery.

Sensorineural Hearing Loss (involves inner ear)

Hearing loss that occurs when there is a problem in the way the inner ear or hearing nerve works.

Mixed Hearing Loss (the combination of two)

Hearing loss that includes both a conductive and a sensorineural hearing loss.

Auditory Neuropathy Spectrum Disorder

Hearing loss that occurs when sound enters the ear normally, but because of damage to the inner ear or the hearing nerve, the sound isn’t organized in a way that the brain can understand.

Prevention is always better than cure

You should take the following precautions to prevent noise-induced hearing loss and worsening of age-related hearing impairment:

1. Limit exposure to loud noises and protect yourself from high-intensity sound exposure. If you are at risk of exposure, then wear earplugs.
2. Have routine ear check-ups and hearing tested if you are at risk
3. Avoid listening to rock concerts for long. If you are used to, then take intermittent breaks.
4. Turn down volume if music is loud.
5. Don’t use earphones for long
6. Never try yourself to clean earwax – take professional help if you have excess earwax.
7. Take extra precautions if you are prone to ear infections especially during swimming, aeroplane travel or when you are having cold symptoms.

Kindly visit an ENT doctor and seek medical advice if you have:

• Ear infections induced hearing loss.
• Sudden hearing loss that has occurred in a few hours or less than three days in one or both the ears.
• Problems listening to the conversation in background noise.
• To repeatedly increase the volume of TV and Radio

Hearing Loss Treatment

Treatment for hearing loss depends on the cause and severity of the problem.

For instance, if hearing loss is temporary due to excess wax build-up, then removing wax blockage can help. Your doctor is the best person to do this job. Never try to remove earwax at home by yourself as it does more harm to you than good.

Hearing loss due to ear infections can be treated by draining the excess fluid build-up by insertion of tubes. Your ENT doctor helps you with this.

If hearing loss is due to structural abnormalities or growth of tissues or due to abnormalities in the bones or hearing and eardrum, your ENT doctor treats your condition with surgery.

Hearing Aids

Your ENT specialist may recommend a hearing aid to you if your hearing loss is due to inner ear issues. You can discuss the advantages of using a hearing aid with your audiologist before you get one for you. There are many options currently available in the market but open fit ones are the most popular ones. You can select the best one according to your needs.

Cochlear Implant

It is a device implanted inside the ear in the cochlea for amplification of sounds. The device uses a sound processor, receiver and electrodes. The sound processor fits behind the ear. It captures sound signals and transmits those signals to a receiver implanted behind the ear. The receiver transmits the signals to the electrodes implanted in the cochlea. The auditory nerve transmits the signals to the brain. The brain processes electrical signals into sound. A cochlear implant is useful for people who have severe hearing loss from inner-ear damage.

Cochlear implant benefits people who can no longer use a hearing aid. Over a period of time and with intensive practice, these implants can improve communication and quality of life of the people having them.