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摘要I摘要近年来，因环境噪声污染、意外事故导致耳聋的人数逐渐增多。这一人数众多、特殊困难的残疾人群体，已引起全社会，特别是卫生部门的高度重视。本文设计的听力测试仪由信号发生器和频率计并联复合而成，融合了这两分支电路，并通过串口将数据上传至上位机，存储进数据库，为听力保护提供可参考的数据。本论文主要针对整个听力测试仪系统进行了研究设计。具体如下：先设计一个信号发生器，再设计功率放大器，将信号发生器产生的信号送给功率放大器，同时将信号发生器输出另一路送进到单片机里，用单片机读取出信号的频率，进而显示在液晶显示器上，与此同时，把信号的频率向上位机进行传送，将采集到的数据送入电脑，并且存入数据库中，以试验数据为依据，同步测算不同人能听到的频率范围，根据数据，为被测试者提供相应的听力保护建议，从而更好有效保护听力。关键词：听力测试仪；频率；信号发生；功放AbstractIIAbstractInrecentyears,duetotheenvironmentalnoisepollution,anaccidentthatthenumberofdeafnessincreasegradually.Thisnumber,specialdifficultiesofthedisabledgroup,hascausedthewholesociety,especiallytheattentionofthehealthdepartment.Inthispaperthedesignbyhearingtestersignalgeneratorandthefrequencymeterparallelcompoundandinto,shirt-sleevethetwobranchcircuit,andthroughaserialportwilluploaddatafirstplacemachine,storedinthedatabase,forhearingprotectioncanprovidereferencetodata.Thisthesismainlyforthewholelisteningtestinstrumentsystemdesign.Providingthemwiththecorrespondinghearingprotectionadvicetobetterprotecteffectivelistening.Keywords:thehearingtestinstrument;Frequency;Signaloccurred;Poweramplifier目录I目录摘要·····························································································IAbstract······················································································II1绪论··························································································11.1听力测试仪研究背景和研究现况··················································11.1.1听力测试仪研究背景··························································11.1.2听力测试仪国内外研究现况·················································11.2听力测试仪技术的研究目的及意义··············································11.3听力测试仪设计方法·································································21.4课题任务要求和目标实现···························································22系统总体方案设计·····································································32.1总体方案描述·········································································32.1.1总计方案的控制综述··························································32.1.2总计方案系统结构·····························································32.2工程标准···············································································32.2.1课题的设计标准································································32.2.2课题的设计原则································································42.3总体方案的确定······································································42.3.1多种方案的理论定性描述····················································42.3.2方案论证与选择································································42.3.3可选方案优化设计·····························································53系统硬件电路设计·····································································63.1硬件电路的构成与电路设计·······················································63.1.1功放电路设计···································································63.1.2信号发生器电路设计··························································123.1.3显示电路设计···································································143.2电路调试···············································································153.2.1功放电路调试···································································153.2.2信号发生电路调试·····························································154系统软件设计············································································16目录II4.1下位机程序设计·····································································164.2上位机程序设计·····································································195系统调试················································································28结论····························································································32致谢····························································································33参考文献·····················································································34附录····························································································35河北工程大学毕业论文31绪论1.1听力测试仪研究背景和研究现况1.1.1听力测试仪研究背景纯音听阈测定是受检耳对不同频率的纯音恰能听到的最轻声音，是判断听敏度的标准行为测听法，按gb7583-87规定某人的听阈是在规定条件下，以一规定的声信号，在多次重复试验中，有一半以上的次数能正确引起听觉的最小声压级。同时纯音测听法是现代较为普及的一种听力测试方法，是一种既能定性又能定量的听力测验法，可判断分析听力损失的程度和性质。1.1.2听力测试仪国内外研究状况听力计的品种有三种：手控听力计(manualaudiometer)，自动记录听力计(automaticaudiometer)，和电脑控制测听听力计(micro-processingaudiometer)。而一个完整的、功能齐全的听力计，至少有三十多种测试功能，包括气导纯音测听、骨导纯音测听、言语测试，掩蔽声、多频道控制、病人反馈，特殊测试等。纯音听力计是听功能测试的声学电子仪器,可为听力损失的定性、定量和定位诊断提供参数依据,是近代耳病诊治和听力学研究的重要设备。系统采用微处理器MEG128控制信号发生电路、音量控制系统、通讯接口和电源等功能模块的协同工作,通过串行通讯实现上、下位机的数据传输。上位PC机完成人机交互的功能,医生通过应用程序设置测试参数、观察检测状态并记录病人信息,并可随时调出已存储的听力数据,便于及时诊断和提供治疗方案。由于白噪声的实现方法复杂多样,且要求质量高、可控性强,因此产生稳定高质的噪声信号是系统开发的重点和难点。设计中通过采用优化的随机算法、精密的后期处理、高效的D/A转换电路等手段输出符合国标要求的声音信号,在实际应用中取得了良好的效果。手控听力计：常用的有国产TLJ-1型，进口MadsenTBH-85型以及西德、丹麦产品等。1.2听力测试仪技术的研究目的及意义听力计是测定个体对各种频率感受性大小的仪器，通过与正常听觉相比，就河北工程大学毕业论文4可确定被试的听力损失情况。心理学上的听力计通常都是指纯音听力计。使用时，仪器主件自动提供由弱到强的各种频率刺激，自动变换频率，测听时被试戴上封闭隔音的耳机，当听到声音时，即按键，仪器可根据被试反应直接绘出可听度曲线。在医学上经常使用听力计来检查听力和测量听力的损失，听力损失的程度是用低于正常阈限的分贝数来衡量的。听力测定能评定一个人的听觉。因此，它在