Hearing impairment is a general term used to describe a decrease in hearing in one or both ears. The decrease in hearing is in the ability to either detect or understand sounds. A complete loss of hearing in one or both ears is usually referred to as deafness. A wide range of medical, genetic and environmental factors may cause hearing impairment or deafness.
Sound is delivered to the ear in the form of sound waves which vary in frequency and amplitude. Frequency refers to the number of cycles per second of the sound wave, while amplitude is the variation in the peak of the wave. A hearing impairment is present when some sound wave frequencies cannot be detected or when low-amplitude sound waves are undetectable.
The level of hearing loss is scientifically measured by determining how loud a sound must be before it can be detected by the test subject. The sound level is measured in decibels, and the range of decibels required determines if hearing loss is mild, moderate, severe or profound.
Hearing Impairment Symptoms
The early symptoms of hearing loss include difficulty in hearing conversations, misunderstanding what other people have said and frequently asking others to repeat themselves. There may be problems in hearing sounds in the environment, such as the chirping of birds. Tinnitus, or ringing in the ears, is another early symptom of hearing impairment.
There are two basic types of hearing impairment: conductive and sensorineural. Each requires a different diagnosis and treatment. Some individuals may experience a combination of these types and require additional strategies.
Conductive hearing loss occurs when sound is not fully conducted from the outer ear to the inner ear. Some hearing may be possible in this case, but sound must be amplified in order to be fully understood. This type of hearing loss can occur when an ear canal obstruction exists or when there are abnormalities in the middle or inner ear.
Sensorineural hearing loss occurs when there is impairment to the auditory nervous system or when the inner ear or cochlea is insensitive to sound waves. This type of impairment is classified as a disability under the Americans with Disabilities Act and can result in eligibility for disability payments for people who are unable to work because of the hearing impairment.
Hearing impairment can have a variety of causes. Hearing loss and deafness may be genetic or may be brought on by disease or illness. Exposure to environmental noise over a long-term period can cause damage hearing. Certain medications and toxic chemicals can cause either reversible or irreversible hearing loss. Hearing loss can also occur as the result of physical trauma, especially head injuries. Advancing age is another cause of hearing impairment.
Hearing Impairment Diagnosis
When a hearing impairment is suspected, a doctor will take the patient’s medical history and perform a physical exam. Initial screening tests will be performed to determine hearing levels. For example, to determine hearing sensitivity a test called a behavioral audiogram may be performed. Different sound frequencies levels are tested to determine the quietest sound that the subject can detect.
When a hearing impairment is indicated, the patient is usually referred to an audiologist to determine the severity and cause of the hearing impairment. The audiologist will use a number of different clinical tests and tools to determine the level of impairment and then suggest a course of treatment.
Hearing Impairment Treatment
The treatment for hearing impairment varies according to the cause and type of hearing loss in a patient. For many types of conductive hearing loss, a medical or surgical procedure can correct obstruction in the ear canal and improve hearing.
Sensorineural hearing loss is usually permanent in nature and is treated with hearing aids or other listening devices such as cochlear implants. Patients who must live with permanent hearing loss can learn coping strategies; including standing at close proximity to people they are talking to and paying attention to the speaker’s face, gestures and tone of voice.
For individuals with severe and profound hearing loss, communication may be done via sign language. Special devices such as telephones which transmit typed text and closed captioning for television viewing can be used to aid in communication.
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