10 common causes of hearing loss

A large portion of the population has some form of hearing loss. In fact, the World Health Organisation estimates that there are 466 million persons in the world with disabling hearing loss (6.1% of the world's population).

There are plenty of causes that contribute to this climbing number, ranging from acute, physical damage to the ear to the natural aging process. While each cause of hearing loss is unique, the most common causes for a Kiwi to have a hearing loss are narrowed down to these 10 things.

1. Physical damage to the ear

Exposure to loud noise over time may cause wear and tear on your auditory nerve cells, which are used to send signals directly to your brain. As a result of this physical trauma, these signals aren't transmitted as effectively and hearing loss occurs.

Usually, it's the higher pitched tones that become difficult to hear and hearing words through background noise become increasingly muffled.

2. Earwax buildup

Your ear canal produces a waxy oil called cerumen (otherwise known as earwax), which is the body's natural way of protecting your ears from dust and microorganisms. In some cases, your glands may produce more earwax than is necessary, resulting in blockage of the ear canal.

Many people make the mistake of cleaning out their ear with a q-tip, and accidentally push the wax deeper into the ear canal, causing a blockage. Some of the symptoms of earwax buildup include:

- pain in your ear
- drainage from the ear
- hearing loss and muffled sounds
- feeling off balance

It's always best practice to seek medical help if you suspect your hearing loss is a result of earwax buildup. Earwax can be safely removed before the buildup escalates into an ear infection.

3. Ear infection

While ear infections are quite common, especially in children, few people are aware that infections can cause conductive hearing loss. Fluid can build up behind the eardrum as a result of the infection, that obstructs the movement of your ear drum and the tiny bones surrounding it. When this occurs, sounds are not efficiently sent to the auditory nerve, causing a temporary hearing loss.

Fortunately, this kind of hearing loss is usually temporary, and once your infection is cleared and the fluid buildup is relieved, your hearing will return to normal.

4. Ruptured ear drum

A ruptured ear drum can happen very suddenly and without warning - you may feel a sharp pain in your ear, or you may notice that pain in your ear subsides quickly as pressure is released. Commonly, when earwax or fluid from an infection is built up, the pressure can become so immense that it tears the membrane, causing damage and hearing loss.

The eardrum serves two important functions in your ear. It senses vibrating sound waves and converts the vibration into wave patterns that our nervous system translates as sound. Depending on the size and location of the tear, this can complicate the sound transmission process and cause a degree of hearing loss until the tear has healed.

5. Ototoxic drugs

Ototoxic drugs are defined as any substance poisonous to the ear, specifically the cochlea or auditory nerve. These can even be regular, prescribed medications that over time will contribute to tinnitus or hearing loss.

Some of these drugs/treatments can include:

- painkillers
- chemotherapy
- anti-inflammatory drugs
- diuretics (used to treat high blood pressure)
- Some antibiotics (namely; gentamicin, streptomycin, or neomycin)

These medications can damage the sensory cells used for hearing and balance. Your symptoms may begin with a ringing (or tinnitus) and gradual loss of hearing.

If you suspect a medication you are taking is impairing your ability to hear, it may be worth consulting with your doctor to reduce your dosage or stop the medication altogether to protect your ears.

6. Smoking causes hearing loss

Many studies have shown that exposure to tobacco smoke (directly, second-hand or even in utero) can directly impact your hearing health.

The effects of nicotine and carbon monoxide can include:

- lower oxygen blood levels and constrict blood vessels all over your body, including the ear
- interference with neurotransmitters in the auditory nerve
- irritation of the Eustachian tube and lining of the middle ear making you more sensitive to loud noises

If you smoke and are experiencing the side effects of hearing loss, make quitting a priority in order to protect your hearing and prevent further loss.

7. Diabetes as precursor to hearing loss

Diabetes is, put simply, the bodies inability to produce and/or manage insulin appropriately. According to NZ Ministry of Health studies, "there are over 240,000 people in New Zealand who have been diagnosed with diabetes (mostly type 2). It is thought there are another 100,000 people who have it but don’t know."

Because of the high rate of diabetes and its connection to hearing loss, it's no wonder this is one of the most common causes of hearing impairment in NZ.

Your inner ears rely on good circulation to maintain health. Diabetes can cause high blood glucose levels which can cause damage to the small blood vessels in the inner ear, resulting in hearing loss.

8. Acoustic neuroma/vestibular schwannoma (or tumour)

An acoustic neuroma, also known as a vestibular schwannoma, is a non-cancerous, slow-growing tumor that can develop on the main nerve leading from your inner ear to your brain. The symptoms of this can be subtle and take years to become noticeable as the tumor grows. However, the most common symptoms are gradual hearing loss, more pronounced on one side, and the onset of tinnitus (usually on the same side as the hearing loss). The pressure from the tumor on adjacent nerves can also cause issues with balance.

9. Hereditary hearing loss

Hereditary hearing loss, which is related to genetics, can be present from birth, or in some cases will develop later in life with a delayed onset. It is believed that there are over 400 forms of genetic hearing loss. Usually this occurs when a dominant or recessive gene is passed down from a parent to a child and cannot be prevented.

10. Hearing loss and the aging process

Age-related hearing loss, or presbycusis, is the slow loss of hearing that occurs as people get older.

Hearing loss occurs when the tiny hair cells in your ears are damaged or die, and as these cells do not regrow, damage over time is permanent. The causes of age-related hearing loss occur over your lifetime and the degree of loss depends on the following:

- genetics
- environment exposure
- pathophysiological changes related to aging (changes in heart health etc.)

If you suspect you're experiencing hearing loss, take our hearing loss quiz and find out if it's time to find a solution to improve your hearing.