Hearing Loss Information
Nearly 30 million Americans have impaired hearing - that's one in ten of the general population and one in three persons over the age of 60. Medical devices such as hearing aids and rehabilitation can substantially reduce hearing loss in the vast majority of patients.
When describing hearing loss we generally look at three attributes: type of hearing loss, degree of hearing loss, and the configuration of the hearing loss.
Types of Hearing Loss
Physicians classify hearing loss as either "conductive", "sensorineural" or "mixed".
Conductive hearing loss occurs when there is a problem with the ear canal, the eardrum and/or the middle ear including the three bones connected to the eardrum. Common reasons for this type of hearing loss are a plug of excess wax in the ear canal, fluid behind the eardrum or an infection in the ear canal. Medical treatment or surgery may be available for these and more complex forms of conductive hearing loss.
Sensorineural hearing loss occurs as a result of damage to the inner ear (cochlea) or auditory nerve, often as a result of the aging process and/or noise exposure. Sounds may be unclear and/or too soft. Sensitivity to loud sounds may occur. Medical or surgical intervention cannot correct most sensorineural hearing losses. However, hearing aids may help you reclaim some sounds that you are missing as a result of nerve deafness.
Mixed hearing loss is a combination of both conductive and sensorineural type hearing problems.
Degree of Hearing Loss
Degree of hearing loss refers to the severity of the loss. The numbers are representative of the patient's thresholds, or the softest intensity at which sound is perceived. The following is one of the more commonly used classification systems:
| Degree of Hearing Loss |
Hearing Loss Range (db HL) |
| Normal |
-10 to 15 |
| Slight |
16 to 25 |
| Mild |
26 to 40 |
| Moderate |
41 to 55 |
| Moderately Severe |
56 to 70 |
| Severe |
71 to 90 |
| Profound |
91+ |
Configuration of Hearing Loss
The configuration or shape of the hearing loss refers to the extent of hearing loss at each frequency and the overall picture of hearing that is created. For example, a hearing loss that only affects the high frequencies would be described as a high-frequency loss. Its configuration would show good hearing in the low frequencies and poor hearing in the high frequencies. On the other hand, if only the low frequencies are affected, the configuration would show poorer hearing for low tones and better hearing for high tones. Some hearing loss configurations are flat, indicating the same amount of hearing loss for low and high tones.
Other Descriptors Associated With Hearing Loss
- Bilateral versus unilateral. Bilateral hearing loss means both ears are affected. Unilateral hearing loss means only one ear is affected.
- Symmetrical versus asymmetrical. Symmetrical hearing loss means that the degree and configuration of hearing loss are the same in each ear. An asymmetrical hearing loss is one in which the degree and/or configuration of the loss is different for each ear.
- Progressive versus sudden hearing loss. Progressive hearing loss is a hearing loss that becomes increasingly worse over time. A sudden hearing loss is one that has an acute or rapid onset and therefore occurs quickly, requiring immediate medical attention to determine its cause and treatment.
- Fluctuating versus stable hearing loss. Some hearing losses change-sometimes getting better, sometimes getting worse. Fluctuating hearing loss is typically a symptom of conductive hearing loss caused by ear infection and middle ear fluid, but also presents in other conditions such as Meniere's disease.
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