《机械工程概论英语语论文》由会员分享，可在线阅读，更多相关《机械工程概论英语语论文（10页珍藏版）》请在金锄头文库上搜索。
1、机械工程概论双语课 题： 助听器 姓 名： 谭伟学 号： 20127733指 导 教 师： 李怀仙完 成 日 期： 2012年12月27日成 绩： AbstractIts easy to take sound for granted, but when you lose it ,due to a serious hearing disorder。How do you do ?thankfully this tiny hearing aid bring back the music Loose of hearing causes a serious handicap, but happily I
2、t can be remedied thanks to hearing aid. A hearing aid is an electric device which typically fits in or behind the wearers ear, and is designed to amplify and modulate sound for the wearer. Earlier devices, known as ear trumpets or ear horns,Similar devices include the bone anchored hearing aid, and
3、 cochlear implant.图 1 Invisible hearing aid1. Introduce about hearing AidHearing Aid is a help to Hearing crippled improve Hearing impairment, and further increase the session with others of the communication ability of tools, equipment, equipment and instrument, etc. Hearing AIDS have the power and
4、 the power of the two kinds, the latter at present has been abandoned. The former and tube type and transistor type two kinds. Transistor type hearing aid the most clever light, appeared in 1950 after replace valve type and is widely used. In a broad sense that can effectively put the sound to the e
5、ar various device can see as hearing AIDS, a narrow sense about hearing aid is a electroacoustic amplifier, through it will put the deaf hear voice ambassador to the original can not hear clearly, cant hear voice, this device is hearing aid. 2. Hearing aid development historyIn 1878, the United Stat
6、es scientists Bell invented the first carbon type hearing aid. The hearing aid is by carbon microphone, headphones, battery, wire etc have been assembled.In 1890, Austrian scientist Ferdinant Alt preparation out of the first generation tube hearing aid.In 1920, thermionic valve (hot cathode tube) wa
7、s soon, appear vacuum tube hearing aid. With the developing of the technology of vacuum tubes, hearing aid volume gradually become smaller, realize the host and the separation of the battery.In 1943, began to develop integrated type hearing aid, the power supply, microphone and amplifier installed i
8、n a small box, hearing AIDS in the volume of more and more small, finally, race like cigarette case, carry has very convenient.In 1948, semiconductor, electronic engineers came immediately semiconductor technology applied in hearing AIDS, and obtain good results. The part of the semiconductor device
9、, can make the volume of hearing AIDS further narrowed.In 1956, made a bte hearing aid, not only further reduced volume, advantages more than the glasses type and cassette hearing aid.In 1957, the ear type hearing aid was published, the emergence of tantalum capacitor, capacitance volume further red
10、uced, transistor circuit to integrated circuit the miniaturization orientation rapid development. Along with large scale integrated circuit, the emergence of the volume of hearing AIDS further reduced, the ear type hearing aid after appearing soon, half ear a cavity, ear canal type, complete the ear
11、 canal type hearing aid arise, to a great extent, satisfy the patients psychological and beautiful on needs.1982 electret microphone to realize the advent of hearing AIDS miniaturization, sensitivity and resolution was to reach a new level.In 1990, the computer programming hearing aid appeared.In 19
12、97, the digital hearing aid gain intelligent adjustment, use very convenient, performance reached higher level.So after a long time of development hearing aid technology has very mature.3. Type of Hearing aid 3.1The cassette hearing AIDS This are cheaper, but shape is too big, difficult to use, and
13、the function of shortcomings, such as less.图 2 cassette hearing AIDS3.2 Bte hearing AIDS:It like banana curvature, fell in the ear, the average length of about 4 5 cm. Receiver open with a rigid plastic pipe made of guide sound hook connection and hung it on the auricle flange root, which hook the s
14、oft plastic pipe and ear die ear plugs into the ear a cavity and the ear canal. Because of good performance, the cabinet can be made into all kinds of color of skin, fell in the ear for the hair after the concealed, often not to outsiders, it is found that can meet the deaf psychological requirement
15、s图3 bte hearing AIDS3.3 Constant systems hearing AIDS: its main advantages are: appearance compact, easy to conceal, According to the ear canal shape customization, wearing comfortable, not off; Not easy go into water, the sweat, for the hearing aid maintenance.图4 Constant systems hearing AIDS4. Working principleFirst, the microphone receiving voice and put it into the wave form, turn energy into electrical energy. Second, Amplifier amplification signal. Third, headset (receiver) the signal into sound signal. Amplification of electrical signals into die to signal to the proces
