Hearing loss refers to reduced hearing that results from a problem in one or both ears and can affect people of all ages. It usually develops gradually over the years and you may not realise it until damage is done. A study conducted by Singapore’s Ministry of Health in 2010 found that almost 10% of Singaporeans in their 60s suffer from disabling hearing loss. Hearing loss that occurs gradually as you age (presbycusis) is common.
Conductive hearing loss
This happens when sound waves cannot be transmitted properly from the external environment to the cochlea (a sense organ that translates sound into nerve impulses which is sent to the brain). This could be due to a problem in the external ear canal, ear drum, middle ear bones or middle ear space such as:
- Obstruction in the external ear canal – from ear wax, foreign body or infection (otitis externa)
- Perforated ear drum – as a result of trauma or chronic infection
- Dislocated/damaged ossicles – from trauma/ chronic disease
- Otitis media – middle ear infection
Sensorineural hearing loss
This happens when there is damage to the cochlea or the hearing nerve (auditory nerve). This is the most common type of hearing loss in 9 out of 10 people with hearing loss. Sensorineural hearing loss can occur from:
- Ageing (presbycusis)
- Acute/chronic exposure to loud noise
- Infection in the inner ear from viruses and bacteria, e.g. mumps, measles, influenza
- Meniere’s disease, a disease that causes tinnitus, hearing loss and dizziness
- Acoustic neuroma, a tumour of the vestibular nerve
- Ototoxic drugs, certain antibiotics or cancer drugs
Mixed hearing loss
This a combination of both conductive and sensorineural hearing loss.