What Is Hearing Impairment?

• Conductive hearing loss results from a problem with the outer or middle ear, including the ear canal, eardrum, or ossicles. A blockage or other structural problem interferes with how sound gets conducted through the ear, making sound levels seem lower. In many cases, conductive hearing loss can be corrected with medications or surgery .
• Sensorineural (pronounced: sen-so-ree- nyour -ul) hearing loss results from damage to the inner ear (cochlea) or the auditory nerve. The person has trouble hearing clearly, understanding speech, and interpreting various sounds. This type of hearing loss is permanent. It may be treated with hearing aids or, in severe cases, a cochlear implant.
• Mixed hearing loss occurs when someone has both conductive and sensorineural hearing problems.

The degree of hearing impairment can vary widely from person to person. Some people have partial hearing loss, meaning that the ear can pick up some sounds; others have complete hearing loss, meaning that the ear cannot hear at all (people with complete hearing loss are considered deaf). One or both ears may be affected, and the impairment may be worse in one ear than in the other.

The timing of the hearing loss can vary, too. Congenital hearing loss is present at birth or happens within the first few days of life. Acquired hearing loss occurs later in life - during childhood, the teen years, or in adulthood - and it can be sudden or progressive (happening slowly over time).

According to the National Institute on Deafness and Other Communication Disorders, about 28 million Americans are deaf or hearing impaired. That's about one out of every 10 people. Another 30 million are exposed to hazardous noise levels on a regular basis. Hearing loss is also the most common birth anomaly.