What is Hearing Loss?
Hearing loss refers to reduced hearing of a person resulting from a problem in one or more parts of the ear. It can affect people of all ages. Sound waves usually move through the external ear canal and vibrate the eardrum. The vibration of the eardrum is then passed through the middle ear bones onto the cochlea (the hearing organ). The sensory cells of the cochlea are stimulated and signals are transmitted to the auditory nerves (hearing nerves) and the brain which recognises the transmitted signals as sounds.
There are three types of hearing loss:
- Conductive hearing loss - sound waves are not transmitted properly from the outside environment to the cochlea
- Presbycusis - occurs with ageing
- Sensorineural hearing loss - occurs when the cochlea or auditory nerves are damaged
Different causes leading to obstructive hearing loss may include the followings:
- Drugs, including certain antibiotics and cancer drugs, can damage some of the hearing nerves or the sensory cells of the cochlea, and therefore lead to otitis media (a group of inflammatory diseases of the middle ear).
- Problems affecting the external ear canal, eardrum, middle ear bones, or middle ear space:
- Chronic diseases or trauma can cause the eardrum to burst, or the middle ear bones to be dislodged, damaged or fixed.
- Middle ear infection, also known as otitis media, may occur due to a variety of causes including increasing age, inner ear viral and bacterial infections (mumps, measles and influenza), ménière disease (inner ear disorder that affects balance and hearing), and damage to the sensory cells in the cochlea due to acute or chronic exposure to loud noises.
- External ear canal can be blocked by wax or foreign objects, or can be infected.
Hearing loss is characterised by a sudden or gradual onset, and it can affect one or both ears. Symptoms of hearing loss include:
- Difficulty in understanding what other people are saying, especially against background noise
- Earache and ear discharge due to ear infections
- Frequently asking for directions or conversations to be repeated
- Ringing in the ears (tinnitus)
- Speaking louder than normal
- Feeling dizzy and off balance (vertigo)
- Withdrawal from conversations
Treatment of hearing loss depends on the underlying causes. Doctor will evaluate the patient’s condition and suggest treatment that finds most appropriate:
- If hearing loss is caused by ear wax build-up or a foreign body in the ear canal, ENT surgeon can remove it under a microscope.
- If hearing loss is caused by an external ear infection, topical antibiotics may be prescribed.
- If hearing loss is caused by a burst eardrum, treatment will target the underlying cause. Surgical repair may be needed to fix a burst eardrum if it is not repaired within three months, or if you suffer from frequent ear infections and associated ear discharge.
- If hearing loss is caused by certain medications, the doctor may prescribe different medications or advise you to stop taking them.
- If hearing loss is caused by ageing (presbycusis), there is no cure. ENT specialist may recommend the use of a hearing aid depending on the patient’s condition. Otherwise treatment will be aimed at protecting hearing as much as possible to slow down progressive loss.