| 单词 | hearing aid | ||||||
| 释义 | hearing aidhearing aidhearing aidhear′ing aid`n.
hearing aid→ 助听器zhCNhearing aidhearing aid,device used in some forms of deafness to amplify sound before it reaches the auditory organs. Modern hearing aids are electronic. They contain a tiny receiver and a transistor amplifier, and are usually battery powered. Some are small enough to fit into an arm of a pair of eyeglasses, or into the outer ear. The bone-conduction hearing aid, placed behind the ear, channels sound waves to the adjacent bony part of the skull, which then transmits the vibrations to the auditory nerve of the cochlea. The air-conduction hearing aid amplifies sounds and directs them into the ear toward the tympanic membrane. In recent years, a number of advancements have been made to hearing aids, improving the comfort, sensitivity, and aesthetic quality of the devices. Today, many hearing aids are customized to amplify only those noises (e.g., high frequency) that the user has difficulty hearing. Cochlear implants have been developed for use by certain totally deaf people. They consist of mechanical replacements for ineffective hair cells in the inner ear, which transform sound vibrations into electronic impulses that stimulate the auditory nerve.Hearing Aida sound-amplifying device used by persons afflicted with deafness or impaired hearing. The earliest hearing aids were purely acoustic devices, such as ear trumpets, whose narrow end was inserted into the ear. Modern hearing aids are electroacoustic devices consisting of a microphone, an amplifier, and an earphone. The sound enters the microphone, where it is converted into electric voltage. Amplified by electronic tubes or transistors, this voltage enters the earphone, where it is reconverted into amplified sound. Hearing aids differ in design according to the nature of the auditory impairment. The standard earphone, inserted into the ear, transmits amplified sound into the external ear, and the bone conduction receiver, pressed against the mastoid process of the temporal bone, transmits sound into the inner ear. Miniature hearing aids have a miniature earphone that is attached to an individually molded insert in the external ear. Some hearing aids are built into eyeglass frames or hair clips. Pocket hearing aids are manufactured as well. Hearing aids are prescribed by a physician and individually fitted in specialized laboratories after exhaustive hearing tests. hearing aid[′hir·iŋ ‚ād]hearing aidhearing aidhearing[hēr´ing] Those who have conductive hearing loss can often use any one of the better aids with good results. Patients with otosclerosis will probably need the bone-conduction type of instrument. Those with sensorineural hearing loss (caused by injury to the vestibulocochlear nerve), or a mixed type, may have more trouble selecting a suitable hearing aid and may get less satisfactory results. Those wearing a hearing aid for the first time should have special training in its proper use. A hearing aid picks up and amplifies all sounds in the vicinity. Often a person whose hearing has declined gradually will have lost the facility to ignore background noises. When one first tries a hearing aid, one's ears will be assaulted by the sounds of passing cars, of doors slamming, of telephones ringing. Training in how to filter out these noises and concentrate on the essential is necessary if the person is to get good results from the hearing aid. For best results, this should be combined with lessons in lipreading. A cochlear implant can help profoundly deaf persons recognize and interpret various sounds. It does not restore hearing but can improve the quality of life for the deaf.  hear·ing aid(hēr'ing ād),hearing aidhearing aidAudiology A battery-powered electro-acoustic device that brings amplified sound to the ear to improve hearing, generally worn in the ear. See Hearing loss.hear·ing aid(hēr'ing ād)Synonym(s): hearing instrument. hearing aidAny device capable of increasing sound intensity at the ear, so as to assist the deaf. Electronic hearing aids traditionally consist of a microphone, an integrated circuit amplifier and an earpiece, often combined into a single device. Many include an electro-magnetic pickup for use in buildings or with telephones equipped with electro-magnetic sound radiation devices. Latest designs are intended for ear implantation and, instead of producing amplified sound from an earphone, apply output vibrations directly to the auditory ossicles, so eliminating feedback squeal. Amplification cannot relieve all cases of deafness.hear·ing aid(hēr'ing ād)hearing aid
Synonyms for hearing aid
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hearing aid - an electronic device that amplifies sound and is worn to compensate for poor hearing