Hearing loss can be split into three main types that describe the underlying cause for the decreased hearing ability that a patient is experiencing. These types of hearing loss have differing symptoms and treatment options.
The most common type of hearing loss is known as sensorineural hearing loss. It is a permanent hearing loss that occurs when there is damage to either the tiny hair-like cells of the inner ear or the auditory nerve itself, which prevents or weakens the transfer of nerve signals to the brain. These signals that are blocked carry information about the loudness and clarity of sounds.
If a child is born with sensorineural hearing loss, it is most likely due to a genetic syndrome or an infection passed from mother to fetus inside the womb, such as toxoplasmosis, rubella or herpes. When sensorineural hearing loss develops later in life, it can be caused by a wide variety of triggers, including:
The symptoms of sensorineural hearing loss affect both the loudness and the clarity of sounds:
There is no medical or surgical method of repairing the tiny hair-like cells of the inner ear or the auditory nerve if they are damaged. However, sensorineural hearing loss can be treated quite successfully with hearing aids or cochlear implants, depending on the severity of the loss. Assistive listening devices, like alerting devices, vibrating alarm clocks and captioned phones help provide a complete hearing solution.
A less common type of hearing loss is conductive hearing loss, which occurs when there is an obstruction or damage to the outer or middle ear that prevents sound from being conducted to the inner ear. Conductive hearing loss may be temporary or permanent, depending on the cause.
The causes of conductive hearing loss can be differentiated by which part of the ear they affect - either the outer or middle ear:
|Did you know individuals with sensorineural hearing loss often complain they can hear people speaking, just not clearly. Another symptom is thinking people are mumbling.|
Because the sensitive inner ear and auditory nerve are intact, an individual suffering from conductive hearing loss primarily has difficulty with the overall loudness of sounds, but not the clarity. Individuals with this kind of loss often find that turning up the volume of the radio or television is all it takes to improve their ability to hear. The following symptoms are also consistent with this type of loss:
There are sometimes medical or surgical treatments that can improve hearing ability for those with conductive hearing loss. For example, conductive losses caused by wax impactions, foreign objects, abnormal growths or ear infections can often be corrected with medical treatments, like extraction of earwax, antibiotics or surgical procedures. These causes usually result in temporary hearing losses. The treating physician and hearing healthcare professional will monitor hearing ability and work with the patient to determine when and if a hearing solution is needed.
Conductive hearing losses caused by other abnormalities, like stenosis of the ear canal, exostoses, otosclerosis and ossicular chain discontinuity are more difficult to treat medically and may be considered a permanent hearing loss. These conductive losses may be treated with traditional or bone-conduction hearing aids, bone-anchored implantable devices or middle ear implants. Assistive listening devices, like amplified telephones or headphones for television, may help provide a complete hearing solution.
Mixed hearing loss
Mixed hearing loss is any combination of sensorineural and conductive hearing loss.
Mixed hearing loss commonly occurs when the ear sustains some sort of trauma. It can also happen gradually over time, when one hearing loss is compounded by another. For example, an individual with a long-standing conductive hearing loss might experience presbycusis as they age. Alternatively, an individual with sensorineural hearing loss may have a temporary mixed hearing loss due to wax impaction.
The symptoms of mixed hearing loss will be some combination of those listed above for the other two types of hearing loss.
Treatment options for mixed hearing loss will depend on whether the loss is more sensorineural or conductive in nature. If a greater portion of the loss is caused by a conductive component, surgical procedures and other medical treatments might be more effective in correcting the hearing concerns. If a greater portion of the loss is sensorineural, hearing aids or implantable devices may be the best option.
If you (or your loved ones) think you might have a hearing loss, it's important to consult with a physician and a hearing healthcare professional to investigate the cause and corresponding treatment options. Many conductive and mixed hearing losses can be remediated with medical intervention and all hearing loss is treatable with hearing aids, implantable devices and/or assistive listening devices.
This content was last reviewed on: April 22nd, 2014