What Causes Hearing Loss?

Elderly man with his hand behind is hear to hear better indicating he has a hearing loss.

To better understand what causes hearing loss, it’s important to understand how the ear works. The ear is made up of 3 parts, namely the outer, middle, and inner ear. The outer ear consists of the pinna and the ear canal; the middle ear consists of the eardrum, the three tiniest bones in the body, and the Eustachian tube; and the inner ear consists of the cochlea which is responsible for hearing and the semi-circular canals responsible for balance.

The outer ear and the middle ear are largely responsible for conducting (or transporting) sounds, whilst the inner ear converts the information so that the nerve can take it to the brain. A hearing difficulty caused by the outer and /or middle ear is therefore referred to as a conductive hearing loss (CHL), whilst hearing difficulty caused by the inner ear only is referred to as a sensorineural hearing loss (SNHL). Hearing difficulty caused by the inner ear and the conductive component is referred to as a mixed hearing loss (MHL). Conductive hearing loss is usually treatable and in many cases, reversible, however sensorineural hearing loss is not always reversible.

Conductive hearing losses can often be caused by the following:

• Middle ear infections or fluid in the middle ear due to colds or allergies
• A perforated eardrum due to an infection or accident
• Poor eustachian tube function often due to colds or allergies
• Grommets or t-tubes as part of the treatment of middle ear infections
• Wax causing a blockage
• Infections of the ear canal, also known as swimmer’s ear
• Objects that get stuck in the ear canal
• Malformed outer or middle ear
• Otosclerosis
• Ossicular discontinuity due to accidents
• Tumors that block the outer or middle ear.

Sensorineural hearing losses can present before birth due to predisposing factors.

There are also other health-related and habitual causes:

• A family history of hearing loss
• Complications, substance use, maternal infections, during the pregnancy, or premature birth
• Syndromes
• Head trauma damages any part of the hearing system
• Age
• Noise exposure
• Ototoxic medication, especially for the treatment of multidrug-resistant tuberculosis and treatment for cancer
• Other side effects of cumulative medicine use
• Infections like mumps or measles
• Auto-immune inner ear disease
• Meniere’s disease
• Acoustic neuroma or other cancerous growths in the inner ear or anywhere on the auditory pathway
• Heart disease
• Diabetes
• Stroke
• Obesity
• Hypertension
• Smoking
The main causes of hearing loss in children and adults are different, however, the symptoms may be the same. Any hearing loss will affect the loudness and clarity of sound.

Common complaints are:

• Difficulty hearing in noisy environments
• Noises are too loud and can be uncomfortable
• Women and children’s voices are most difficult to hear
• Having a sensation of pain or pressure in the ears
• A feeling of being off-balance or dizzy
• Difficulty hearing the television or on the phone
• Other people complain that you speak too loud
• Being distracted and tired most of the time
• Ringing, humming, buzzing sound in the ears

It is important to be proactive and monitor your hearing if you are predisposed to getting hearing loss. Speak to your health care provider if you are unsure whether you are predisposed to hearing loss.
If you wait too long, it could become especially difficult to treat a hearing loss.

 

Hema Thakor

Written byHema Thakor

B. Speech-Language Pathology and Audiology

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