Hearing impaired people have trouble hearing the full range of frequencies on the auditory spectrum. Some people are born with hearing impairments, while many others develop them over the course of time, due to illness, injury, disease, old age, or exposure to loud noises. Hearing impaired people may have mild, moderate, severe, or profound hearing loss, or they may suffer from total deafness. Most hearing impaired people are hard of hearing, but can benefit from assistive devices like hearing aids. Those suffering from severe, profound or complete hearing loss may use light alarms, sign language, lip reading, and even cochlear implants to facilitate communication and help improve hearing.
Hearing loss is typically categorized as mild, moderate, severe, profound or total, depending on the hearing impaired person's ability to hear sounds clearly. A person with mild hearing impairment should be able to hear sounds measured at 25 to 40 decibels and higher. Those with moderate hearing loss should be able to hear sounds measured at 40 to 70 decibels and higher. Those with severe impairment may only be able to hear sounds measured at 70 to 95 decibels and higher. Persons so hearing impaired that they can't hear sounds at all are considered deaf.
Hearing loss can occur due to a blockage of the outer or middle ear. Blockages can occur due to fluid build-up, wax build-up, foreign objects, tumors, swelling, or disease. This type of hearing loss is known as conductive hearing loss, because it blocks sound waves from reaching the inner ear. Sensorineural hearing loss, a second type of hearing loss, occurs when the structures of the inner ear, the auditory nerve, or the auditory cortex of the brain suffers damage. Both types of hearing loss can occur simultaneously.
Hearing impaired persons may have trouble communicating with others, due to the nature of their impairment. Traditional speech, lip reading, sign language, finger spelling, and writing all provide alternative means of communication for the hearing impaired. Sign language interpreters can help the deaf and hearing impaired understand what's being said to them.
Those who suffer from severe, profound, or total hearing loss often prefer lip reading as the most practical way of understanding a person who is not hearing impaired. Written communication, while often much easier to master, can make some hearing impaired individuals feel more socially isolated. Those without hearing impairments can make themselves more easily understood by the hearing impaired by maintaining eye contact while speaking slowly and clearly.
Hearing aids, light alarms, and other assistive devices can help the hearing impaired perform routine daily tasks. Hearing aids can increase the range of audible sounds for many with hearing impairments, while cochlear implants can benefit those for whom hearing aids are no longer effective. Light alarms can let a hearing impaired person know when the phone is ringing, or when someone is at the door. Closed captions on television programs and text telephones can also be invaluable tools for those with disabling hearing impairments.