本科毕业论文-市售护耳器实际降噪值评估

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1、学号：201095110124毕业论文GRADUATETHESIS论文题目：市售护耳器实际降噪值评估2015年06月02日摘要摘要目的：收集企业常用的6种耳塞，对6名女性志愿者进行听阈测试，通过对各种耳塞的各频段降噪值测量，评估护耳器的实际A声级降噪值，对护耳器的实际降噪效果进行评价，为建设项目职业病危害评价中护耳器的防护效果评价和企业护耳器选用提供有益的参考。方法：本文选择双耳气导听阈<20dB,排除耳鸣、中耳炎病史及噪声接触史的6名女性成年人志愿者作为研究对象，采用纯音气导听阈测听法来测量佩戴耳塞前后的听阈改变。每种耳塞

2、的实际Ａ声级降噪值与其SNR值和NRR值估计的A声级降噪值的比较用单样本t检验，耳塞的实际A声级降噪值与SNR值、NRR值的关联性研究采用SPSS17.0进行统计分析，检验水准定为0.05(双侧检验)。结果：通过对测试结果的分析，计算得到6种耳塞的实际A声级降噪值分别为32.96dB、33.01dB、45.70dB、44.20dB、47.32dB、38.30dB，与耳塞SNR值和NRR值估计的A声级降噪值比较，差异均具有统计学意义；耳塞的实际A声级降噪值与SNR值之间没有明显的关联性，与NRR值有一定的关联性。结论：实验得到

3、的实际A声级降噪值比由耳塞的SNR值和NRR值估计的实际A声级降噪值要高；用NRR值来评价耳塞的防噪效果更贴近耳塞的实际应用。关键词耳塞；纯音气导听阈测听法；A声级降噪值-Ⅰ-AbstractAbstractObjectives:Collecting6kindsofearplugsthatusuallyusedbytheenterprises,thenmeasurethehearingthresholdof6womenvolunteers.Throughmeasurethethresholddenoisingofallfre

4、quencyrangestoestimatetheactualAlevelsnoisereductionoftheearplug,toevaluatetheactualnoisereductioneffectoftheearplug.Itcanprovideausefulreferencefortheevaluationofoccupationalhazardsinconstructionprojectinearplugprotectiveeffectevaluationandselectionofenterpriseear

5、plugs.Methods:Selectingsixadultwomenvolunteersthatwhoseairconductionhearingthresholdsunder20dB,excludetinnitus,otitismediaandnoiseexposurehistory.Usingthepuretoneairconductionthresholdaudiometrytomeasurethechangeofthehearingthresholdafterwithearplug.Usedsingle-samp

6、let-testmodetocomparetheactualAlevelsnoisereductionofeachearplugwithAsoundlevelofnoiseestimatedfromitsSNRvalueandNRRvalue.MakingtherelevancestudyfortheactualAlevelsnoisereductionandNRRvalueorSNRvaluebyusingSPSS17.0,thesignificancelevelis0.05(two-tailed).Results:Ana

7、lysisthetestresults,wecangetthetheactualAlevelsnoisereductionofthe6earplugs.Theyare32.96dB,33.01dB,45.70dB,44.20dB,47.32dB,38.30dB.ComparedwiththeresultsthatcalculatedfromSNRvalueorNRRvalue,thedifferencehasstatisticalsignificance.Thereisnoobviousrelevancebetweenthe

8、actualAlevelsnoisereductionandtheSNRvalue,andhavesomerelevancewiththeNRRvalue.Conclusions:TheactualAlevelsnoisereductionobtainedbytheexperimentis