纯音听力计中纯音信号发生器的设计与实现

Design and Implementation of Pure-tone Signal Generator in Audiometer

纯音听力计是进行听觉功能测试的基本声学仪器,而纯音信号发生器是其最重要的组成模块,它决定着可控声源的质量,直接影响测试结果的准确性;文章分析了现有纯音信号发生器存在的问题,提出了一种基于微处理器ATMEG128的设计与实现方法;该发生器可生成频率在125Hz^8kHz、听力级为-10~120dB的精密纯音信号;其中,频率按1/3倍频程输出,听力级的最小调节精度可达0.5 dB,符合国家标准。

Pure--tone audiometer is a kind of acoustic instruments dealing with measurement of hearing. Pure--tone signal generator is the most important design module. It decides the quality of the sound source and directly affects the accuracy of test results. The article ana- lyzes the problems of existing pure- tone signal generator and presents the design and implementation method based on microprocessor AT- MEG128. This pure--tone generator can output precise pure--tone signal whose frequency range is 125 Hz--8 kHz and hearing level is-10 dB--120dB. The frequency is produced based on 1/3 octave frequency and the adjustment accuracy of hearing level resolution is 0. 5 dB. These are fully in line with National Standard.