tailieunhanh - Chapter 030. Disorders of Smell, Taste, and Hearing (Part 14)

In the event that the hearing aid provides inadequate rehabilitation, cochlear implants may be appropriate. Criteria for implantation include severe to profound hearing loss with word recognition score ≤30% under best aided conditions. Worldwide, 20,000 deaf individuals (including 4000 children) have received cochlear implants. Cochlear implants are neural prostheses that convert sound energy to electrical energy and can be used to stimulate the auditory division of the eighth nerve directly. In most cases of profound hearing impairment, the auditory hair cells are lost but the ganglionic cells of the auditory division of the eighth nerve are preserved. . | Chapter 030. Disorders of Smell Taste and Hearing Part 14 In the event that the hearing aid provides inadequate rehabilitation cochlear implants may be appropriate. Criteria for implantation include severe to profound hearing loss with word recognition score 30 under best aided conditions. Worldwide 20 000 deaf individuals including 4000 children have received cochlear implants. Cochlear implants are neural prostheses that convert sound energy to electrical energy and can be used to stimulate the auditory division of the eighth nerve directly. In most cases of profound hearing impairment the auditory hair cells are lost but the ganglionic cells of the auditory division of the eighth nerve are preserved. Cochlear implants consist of electrodes that are inserted into the cochlea through the round window speech processors that extract acoustical elements of speech for conversion to electrical currents and a means of transmitting the electrical energy through the skin. Patients with implants experience sound that helps with speech reading allows open-set word recognition and helps in modulating the person s own voice. Usually within 3 months after implantation adult patients can understand speech without visual cues. With the current generation of multichannel cochlear implants nearly 75 of patients are able to converse on the telephone. For individuals who have had both eighth nerves destroyed by trauma or bilateral vestibular schwannomas . neurofibromatosis type 2 brainstem auditory implants placed near the cochlear nucleus may provide auditory rehabilitation. Tinnitus often accompanies hearing loss. As for background noise tinnitus can degrade speech comprehension in individuals with hearing impairment. Therapy for tinnitus is usually directed towards minimizing the appreciation of tinnitus. Relief of the tinnitus may be obtained by masking it with background music. Hearing aids are also helpful in tinnitus suppression as are tinnitus maskers devices that present