The Design And Implementation Of Pure Tone Audiometer

Pure tone audiometer is a kind of acoustics electronic equipment dealing with measurement of hearing. It can provide parameters for hearing impairment. It is an important equipment for treatment of ear disease and audiology study. At first the Paper introduced audiometer's development tendency and present situation. Then based on analysis about system structure and function request, the thesis elaborated the instrument's principle of work, soft and hardware design method and the realization process of pure tone and noise signal.The system used the microprocessor MEG128 to control different function modules working together. The modules include signal generator circuit, volume control system, communication interface, power and so on. Through serial communication the instrument achieved data transmission with PC which completed human-computer interaction. Doctor through application program established test parameter, observed examination condition and recorded patient information.He can call out the hearing data which had been saved at any time to help diagnose promptly and Provide Rx.There are not only many methods to produce white noise, but also it needed high quality and flexibility. So the development key point and difficulty is to generate stable high-grade noise signal. The system used optimized stochastic algorithm, precise later period processing, highly effective D/A switch to produce sound signal which conformed standard and it obtained good effect in the practical application.The major work is to complete the design of hardware circuit and debugging of VC.NET programme,completed testing the system and analyzing the results.The system had merits including exquisite, low cost, low power los, practical use and so on. It can be applicable in all levels of hospitals.