According to 2012 World Health Organization (WHO) global estimates on the prevalence of hearing loss, approximately 15% of the world's adult population has some degree of hearing impairment.
The prevalence increases with age – from 1.7% in children to almost 33% in adults older than 65 years.
In South Africa, approximately 10% of the population has significant hearing loss, but only about 2% seek treatment. It takes an average of seven years to seek help.
'Everybody is mumbling'
There are many causes of hearing loss, which can be temporary or permanent. Temporary causes include noise-induced hearing loss, a blocked ear canal and ototoxic medication.
Permanent hearing loss can be inherited (congenital) or caused by loud noise, an ear infection, ageing or injury to the head or ears.
Hearing loss caused by age and exposure to noise are the two most common reasons for gradual loss of hearing. People might complain that everybody is mumbling and get frustrated because they are missing parts of conversations.
According to the National Institute on Deafness and Other Communication disorders (NIDCD), you may be suffering from gradual hearing loss if:
- You sometimes feel embarrassed when you meet new people because you struggle to hear.
- You feel frustrated when talking to family members because you find it difficult to hear them.
- You have difficulty hearing or understanding co-workers, clients or customers.
- You have difficulty hearing when visiting friends, relatives or neighbours.
- You have trouble hearing in the movies or in the theatre.
- Hearing problems cause you to argue with family members.
- You have trouble hearing the TV or radio at levels that are loud enough for others.
- You feel that any difficulty with your hearing limits your personal or social life.
- You have trouble hearing family or friends when you are together in a restaurant.
The NIH explains that loud sounds can be harmful to the ears, both when the exposure is brief and in cases where it is long-lasting. Loud sounds can damage sensitive structures in the inner ear and cause noise induced hearing loss (NIHL). The louder the sound, the more quickly NIHL is likely to happen.
NIHL can have an immediate effect or it can take a while to be noticeable. It can also be temporary or permanent and affect one or both ears. We can safely be exposed to sounds ranging from 0 to 85dB. Anything louder than that can damage our hearing. An ambulance siren measures about 125dB, while normal human speech is around 65dB.
Target shooting and hunting can put you at risk for NIHL, and young adults and teens who listen to their iPods or MP3s through headphones for hours every day are reportedly being diagnosed with hearing at the level of 50-year-olds. Others who frequent nightclubs or play in bands can also experience long-term effects on their hearing.
Effects of ageing
Age-related hearing loss (presbycusis) is one of the most common conditions affecting older adults and gradually happens in most of us as we grow older. It also mostly occurs in both ears and because it happens gradually, many people don't realise that they've lost some of their hearing ability.
According to Action On Hearing Loss, the main cause of age-related hearing loss is wear and tear to the tiny sensory cells known as hair cells in the cochlea. (The cochlea is the spiral-shaped cavity of the inner ear that contains nerve endings essential for hearing.) Genetic factors can, however, also play a part.
Implications of hearing loss
Many people, after being diagnosed with hearing loss, are not keen to admit it, and a US study by the National Council on Aging (NCOA) found that three out of five older subjects who suffer from hearing loss did not use hearing aids.
Studies have found that hearing loss may lead to:
- Irritability and anger
- Tension, stress and depression
- Avoidance of social situations
- Feelings of rejection and loneliness
- Reduced alertness
- Reduced ability to learn new tasks
- Compromised job performance
- Compromised psychological and overall health
How to remedy the situation
Hearing loss that originates in the inner ear and/or auditory nerve, caused by damage to the hair cells is called sensorineural hearing loss.
Sensorineural hearing loss is a permanent condition, and because it's not possible to restore the lost hearing, the best remedy, in cases where hearing loss is not complete, is using a hearing aid.
Image credit: iStock