Hearing impairment is a common complaint, afflicting about 17 percent of all American adults, according to the National Institute on Deafness and Other Communication Disorders. Aging is an important risk factor and nearly half of people older than age 75 have some hearing loss. Men are more likely to suffer the problem than women. Some people only lose certain high-pitched sounds, making it hard to understand the voices of women and children, while others experience more profound losses or even total deafness. There are different types of hearing impairment and they can have different causes.
Conductive Hearing Loss
Conductive hearing loss occurs when something blocks sound waves from reaching the inner ear, according to the National Institute on Deafness and Other Communication Disorders. A patient might experience it as a general loss of volume or the inability to hear faint sounds, according to the American Speech-Language-Hearing Association.
The blockage can be caused by a simple buildup of earwax or fluid, usually from a cold, allergy or ear infection. Sometimes there is a foreign body or a malformation of the ear that causes the problem. Certain injuries like a punctured eardrum or a tumor can also cause conductive hearing loss. This kind of hearing impairment is usually treatable with surgery or other medical intervention.
Presbycusis
Presbycusis is the formal name for the type of hearing impairment that comes on gradually as a person ages, according to the National Institute on Deafness and Other Communication Disorders. It can involve damage to the inner, middle or outer ear as well as the auditory nerve, which converts sounds heard by the ear into nerve impulses the brain can process.
Presbycusis seems to run in families and is thought to have a genetic component. It can also be caused by simple aging, loud noise exposure, head injury, ear infection, illness and by high blood pressure or other circulation problems. Certain types of antibiotics as well as high doses of aspirin can cause hearing loss. Presbycusis can often be helped with hearing aids, medication and sometimes surgery.
Sensorineural Hearing Loss
Sensorineural hearing loss is permanent and not usually treatable, according to the National Institute on Deafness and Other Communication Disorders. It usually involves a reduction in overall volume, loss of ability to hear faint sounds and a loss of clarity that can make it difficult to understand speech, according to the American Speech-Language-Hearing Association. It results from damage to the inner ear or the auditory nerve caused by diseases, birth defects and injuries, certain drugs, exposure to loud noise, viruses, head trauma, aging and tumors. There may also be a genetic component.
Other Situations
Sometimes the causes of hearing loss are mixed and the patient has both a conductive hearing loss that may be treatable and a sensorineural loss that may not be, according to the American Speech-Language-Hearing Association. Sometimes hearing loss affects only one ear. This kind of unilateral hearing loss can affect both adults and children. It can be caused by abnormalities in the ear, illnesses or infections, skull fractures, excessive noise exposure and injury to the brain. It also runs in families and may have a genetic component in some people.
