Our hearing deteriorates naturally with age. In Singapore, 1 out of 11 people are hearing impaired; 4 in 1000 children develop severe to profound hearing loss and about 50% of our population is expected to have significant hearing loss by the time they reach 80 years old.

To contribute to this problem, exposure to noise in today’s environment accelerates hearing loss. As hearing loss occurs gradually, many patients either seek help too late or do not realise that their hearing loss has progressed to the point of needing hearing aids.

When should I get my hearing checked?

Hearing loss is often ignored as symptoms are not too jarring, especially at the beginning. You should get your hearing checked if you notice that you display these symptoms over a period of time:

• Increase the volume of the radio or television to the point that others find it too loud/complain
• Strain to hear conversations
• Frequently ask people to repeat what they’ve said because you can’t hear properly or misunderstand their words
• Watch people’s faces intently to make out their words
• The effort to hear leaves frustrated and tired
• People don’t seem to speak as clearly as they used to
• Experience ear infections, dizziness or ringing in the ears

Causes of hearing loss

The causes of hearing loss include:

• Congenital hearing loss (hearing loss from birth)
• Ear wax Excessive ear digging pushes ear wax deep into the ear canal, impacting the ear canal and causing pain and hearing loss
• Ear infections Ear infections can be bacterial or fungal. They are often caused by injury to the ear canal such as through the use of cotton buds, or if the ear is persistently wet from swimming
• Glue ears This is caused by an accumulation of fluid in the middle ear after a cold or nasal allergy. Most people do not take long to recover from glue ears; if it is persistent, surgery to drain the fluid and equalise the pressure may be required
• Noise-induced hearing loss (exposure to loud noise without protection) Such loud noises include tractors, heavy machinery, live music, power tools and firearms
• Age-related hearing loss
• Exposure to toxic drugs
• Family history of hearing loss
• Personal history of thyroid problems, diabetes, heart disease or circulatory problems
• Exposure to certain drugs 

These include non steroidal anti-inflammatory drugs such as ibuprofen. If certain drugs are causing your hearing loss, consider reducing your dosage or switching to an alternative medication. Discuss your options with your doctor first.

Types of hearing loss

Sound is produced when sound waves vibrate the eardrum. These vibrations are transmitted through the bones of the middle ear to the cochlea, which are then transmitted to the auditory nerve and then relayed as a signal to the brain for processing. Hearing loss is classified according to where the weak link falls in this chain of events. Problems in the middle ear, ear canal or eardrum is referred to as conductive hearing loss, while damage in the auditory nerve or cochlea is known as sensorineural hearing loss.

Sensorineural hearing loss

Many patients with age-related hearing loss find that they can still hear people speaking; they are just unable to make out all the words. This is because hearing loss is often greatest in the high frequencies, meaning consonant sounds like th, t, s and f. For example, many of them cannot differentiate between that, sat, cat or fat.

Sensorineural hearing loss is actually the most common type of age-related hearing loss. This problem usually occurs because of the tiny hair cells along the inner ear that deteriorates. Apart from deteriorating due to age, they can be damaged because of a high fever, prolonged exposure to loud noise, fluid buildup in the inner ear and birth defects.

Those with sensorineural hearing loss often experience an uncomfortable sensitivity to loud sounds or rattling and buzzing sensations. While sensorineural hearing loss is usually not treatable, a hearing aid can help with some of the lost hearing.

Conductive hearing loss

Conductive hearing loss blocks and muffles sound uniformly, similar to if you covered your ears with your hands. It is usually caused by wax blockage, birth defects, ear infections, a hole in the tympanic membrane and heredity factors. This type of hearing loss is caused by the structures in the inner and outer ear that that fail to send sound impulses to the nerve centers.

Conductive hearing loss is often treated with medication or surgery, if not hearing aids when medical treatment is not enough.

Who should I go to for hearing problems?

If you have been experiencing hearing problems, you should first visit an audiologist.

An audiologist is someone who specialises in diagnosing and managing disorders of the auditory and vestibular systems of the ear. He/she will conduct a hearing test to determine if you have hearing loss. If the presence of a medical condition within your ears is detected, the audiologist will refer you to an ENT specialist.

However, if you are experiencing pain or swelling in your ears, then you would want to go straight to an ENT specialist. If your ENT doctor determines that the cause of your ear pain is from hearing loss, then he/she will refer you to an audiologist.

References

1. Korver, A. M., Smith, R. J., Van Camp, G., Schleiss, M. R., Bitner-Glindzicz, M. A., Lustig, L. R., Usami, S. I., & Boudewyns, A. N. (2017). Congenital hearing loss. Nature reviews. Disease primers, 3, 16094. https://doi.org/10.1038/nrdp.2016.94
2. Cunningham, L. L., & Tucci, D. L. (2017). Hearing Loss in Adults. The New England journal of medicine, 377(25), 2465–2473. https://doi.org/10.1056/NEJMra1616601