The National Institutes of Health (NIH) estimates that approximately 37.5 million American adults have a significant hearing loss making it one of the most common health concerns people face. While most causes of hearing loss are well-understood, researchers are still studying all the possible causes, methods for prevention and treatment options. In some cases, no cause can be determined.
Inherited hearing loss
Hereditary hearing loss can be conductive, sensorineural or mixed and is the result of a genetic trait passed down from a parent. A study performed by the University of Washington, Seattle reports there are more than 400 known genetic syndromes that include hearing loss.
Some of these include:
- Waardenburg syndrome
- Branchiootorenal syndrome
- Stickler syndrome
- Usher syndrome
- Pendred syndrome
- Alport syndrome
While many hereditary hearing losses are congenital (present at birth), some of these conditions develop slowly over time.
Age-related hearing loss
Age-related hearing loss, or presbycusis, is the gradual loss of hearing that occurs over time. This type of loss is permanent and is generally greater for higher-pitched tones, such as birds chirping or the ringing of a telephone.
The main symptoms of age-related hearing loss include: difficulty understanding conversations especially in noisy situations, the perception that others are mumbling instead of speaking clearly, certain sounds seeming annoying or too loud and tinnitus (ringing in the ears).
Because presbycusis is a type of sensorineural hearing loss, it commonly occurs from changes in the inner ear as a person ages. It also can be the result of changes in the middle ear or along the nerve pathways leading to the brain. Changes in the blood supply to the ear from heart disease, high blood pressure or vascular conditions may also contribute to age-related hearing loss.
Presbycusis usually affects both ears equally and gradually. Because it develops slowly over time, you may not realize it’s happening until your symptoms become severe or someone else notices you’re having trouble.
What are the signs of hearing loss?
Noise-induced hearing loss
Noise-induced hearing loss is caused by prolonged exposure to loud noise. The culmination of constant exposure to every day sounds like traffic, construction work, noisy office environments or loud music can negatively impact your hearing. While noise-induced hearing loss is generally temporary in nature, repeated overexposure to loud noise makes it harder for the ears to recover between events. The noise damages inner ear hair cells, causing hearing loss to deteriorate over time and become permanent.
Remember: noise-induced hearing loss is largely preventable.
The Center for Disease Control and Prevention estimates that more than one out of 10 people aged 6-19 has already suffered permanent damage to their hearing from excessive exposure to loud noise. Culprits of exposure include: loud music from headphones, stereos and concerts, in addition to construction and other work equipment noises.
You can significantly lower your risk of hearing loss by limiting exposure to loud noises, using earplugs in noisy environments, turning down the volume of music or sound on personal music devices and using a volume-limiter device when using personal audio equipment.
Illness-related hearing loss
There are numerous illnesses and disorders which contribute to hearing loss including:
- Otosclerosis - This disease affects the movement of the tiny bones in the middle ear causing a conductive hearing loss that is usually treated with surgery.
- Meniere’s disease - The cause of this disease is unknown, but symptoms usually include fluctuating hearing loss, vertigo and tinnitus (ringing in the ears).
Unilateral hearing loss
Unilateral hearing loss (UHL), sometimes referred to as Single Sided Deafness (SSD), is hearing loss that occurs in just one ear. It can cause difficulty hearing speech on the affected side and locating the source of sounds.
Causes of unilateral hearing loss include:
- trauma to the ear/head.
- autoimmune ear diseases.
- excessive noise exposure to one ear (shooting long guns is common).
- genetic or hereditary conditions.
- specific syndromes.
- illnesses and infections.
Unilateral hearing loss should be evaluated by an otolaryngologist or other physician. If it is due to a cause that is not medically treatable, specialized hearing aids called CROS (Contralateral Routing of Signal) aids or bone-anchored hearing aids should be considered.
Drug that cause hearing loss
There are numerous types of medications that have been linked to permanent hearing loss, known as ototoxic drugs. These include:
- aminoglycoside antiobiotics.
- aspirin and non-steroidal anti-inflammatory drugs (NSAIDs).
- chemotherapy drugs.
Generally, you must consume large quantities of these types of drugs to notice effects of hearing loss, but research is still being conducted to further understand the effects of specific dosages and medications.
Head trauma and tumors
Another cause for hearing loss is from tumors such as an acoustic neuroma. Tumor-related hearing loss might also include tinnitus (ringing in the ears), or you might have a sensation of fullness in one or both ears. Tumors are usually treated either medically or surgically and normal hearing may or may not be restored.
Head trauma can damage inner ear structures causing a temporary or permanent hearing loss. Any injury sustained to the head should be evaluated by a doctor immediately. The medical evaluation will likely include both a hearing and eye examination.
Cause determines proper treatment
There are so many potential causes of hearing loss. Hearing healthcare professionals are trained to use many diagnostic tests to help get to the bottom of your concerns. Once they determine the cause, they can find the best course of treatment. If you have hearing loss and are unsure of the cause, visit a qualified clinic near you from our consumer-reviewed directory.