Inner Ear Diseases
Diseases of the inner ear can affect the sense of balance and cause symptoms of motion sickness. Anemia, tumors of the acoustic nerve, exposure to abnormal heat, disturbances of the circulatory system, skull injuries, poisoning, emotional disorders, and hyperemia, or increased blood flow, may also cause these symptoms. Ménière’s disease results from abnormalities in the semicircular canals and produces nausea, hearing loss, a disturbed sense of balance, and tinnitus, or a persistent ringing in the ears. Destruction of the inner ear by cryosurgery or ultrasound is sometimes used to combat intractable dizziness.
Damage to the organ of Corti in the inner ear accounts for the condition of many people who are either totally deaf or severely hearing-impaired. Scientists have addressed the difficulties of such people by developing an electronic device called a cochlear implant. This device is more sophisticated than a hearing aid, which merely increases the volume of the sounds that pass through the normal hearing organs. The cochlear implant works by translating sound waves into electric signals. These signals are relayed to electrodes that have been surgically implanted in the cochlea so that the auditory nerve is directly stimulated. After successful surgery, once deaf or severely hearing-impaired patients can usually detect a wide range of sounds, but results depend on factors that include the health of the auditory nerves and the duration of deafness. Nonetheless, lip-reading ability often improves, and implant users have varying degrees of success in using the telephone.
Otalgia, or earache, is not necessarily associated with ear disease; occasionally it is caused by impacted teeth, sinus disease, inflamed tonsils, infections in the nose and pharnyx, or swelling of the lymph nodes in the neck. Tinnitus may also result from these conditions. Permanent tinnitus is most often caused by prolonged exposure to loud noise, which damages the hair cells of the cochlea. A sound masker, worn like a hearing aid, may offer relief to some sufferers by blocking the perception of ringing in the ears.
Damage to the organ of Corti in the inner ear accounts for the condition of many people who are either totally deaf or severely hearing-impaired. Scientists have addressed the difficulties of such people by developing an electronic device called a cochlear implant. This device is more sophisticated than a hearing aid, which merely increases the volume of the sounds that pass through the normal hearing organs. The cochlear implant works by translating sound waves into electric signals. These signals are relayed to electrodes that have been surgically implanted in the cochlea so that the auditory nerve is directly stimulated. After successful surgery, once deaf or severely hearing-impaired patients can usually detect a wide range of sounds, but results depend on factors that include the health of the auditory nerves and the duration of deafness. Nonetheless, lip-reading ability often improves, and implant users have varying degrees of success in using the telephone.
Otalgia, or earache, is not necessarily associated with ear disease; occasionally it is caused by impacted teeth, sinus disease, inflamed tonsils, infections in the nose and pharnyx, or swelling of the lymph nodes in the neck. Tinnitus may also result from these conditions. Permanent tinnitus is most often caused by prolonged exposure to loud noise, which damages the hair cells of the cochlea. A sound masker, worn like a hearing aid, may offer relief to some sufferers by blocking the perception of ringing in the ears.
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