hearing_conservation.pdfVIP专享VIP免费原创优质

OccupationalNoiseExposure29CFR1910.95IsThereaProblem?•Morethan30millionAmericansareexposedtohazardoussoundlevelsonaregularbasis•10millionhavesufferedirreversiblenoiseinducedhearingloss•RateofhearinglossisincreasingintheU.S.GoodHearingisImportant•Worksitescanbedangerous•Whatsoundonaworksitealertsyoutodanger?–backupalarms–vehicletraffic–changesinequipmentnoise–verbalwarningsfromotherworkersGroupExchange•Thinkaboutwhatyourfavoritesoundis?–Couldyouhearyourfavoritesoundifyouhadahearingloss?TheEarisaDelicateToolTHECOCHLEAANDTHEINNEREARAfluidfilledsoundreceptionchamberContainsthousandsoftinyhaircellsThecellsrespondtosoundwavesmadeinthefluidThecellspassthesensationontotheauditorynerveTheCochleaandtheInnerEarSENSORI-NEURALHEARINGLOSSNoise-inducedhearinglossDamagesthehaircellsorauditorynervesIfthenoiseisstoppedhaircellscanbouncebackDamagecanbetemporaryTheCochleaandtheInnerEarSENSORI-NEURALHEARINGLOSSIfthenoisecontinueshaircellscan’tbouncebackDamagecanbepermanent!TheCochleaandtheInnerEarInnerEar•Cochlea–insidearenervecellscalledhaircells•fragile•Continuousnoise–above90dBA•asbadforhaircellsascontinuousfoottrafficistograssThisisyourear.Thisisyourearonnoise.AnyQuestions?WhatisNoise?•Noiseisaphysicalenergythatmovesthroughtheairlikeripplesinapond–noiseisdirectional–noisewillbounceoffwallsandotherobjectsTwoComponentsofNoise•Frequency–perceivedas“pitch”–measuredinhertz(Hz)–humanearmostsensitiveinthe1,000to4,000range•speechfrequencyranges•Intensity–perceivedas“loudness”–measuredindecibels(dB)–“A”scalemimicsthehumanear•usedfornoisesurveysHowisNoiseMeasured?•Soundlevelmeter–instantnoisereadings–generallyAscaleused•mimicsthehumanear•Noisedosimeter–measureaworkersnoiseexposureoverashift•dailydoseofnoise–veryaccurateUnitsofMeasurementforNoise•DecibeldB–littleincreasesonthedecibelscalemakeabigdifference•a6decibelincreaseinnoiseisequaltodoublingtheintensityorloudnessofthenoise•Earprotectionneeded•noiseabove90dBA•recommendedat85dBAExamplesofNoiseLevels•ExamplesatHome•whisperedvoice-20dBA•refrigeratorhum-40dBA•normalconversation-60dBA•averageTV-74dBA•Blender-80dBA•lawnmower-95dBA•Leafblower-110dBA•Chainsaw-115dBANoisyHobbies•Guns•largecalibershortbarrel=130dBA•shotguns&highpoweredrifles=140dBA•Motorcycles•90dBA•Snowmobiles•120dBA•Woodworking•electricdrill=95dBA•powersaw=110dBA•airtools=120dBA•beltsander=93dBA•Walkmanheadsets•90dBA•Rockconcerts•140dBANoiseInTheWorkplace•ExamplesatWork–lawnmower-95dBA–Leafblower-110dBA–Chainsaw-115dBA–poweractuatednailgun-94-117dBA–pneumatichandheldgrinder-101dBA–airhammer-105-130dBA–snowplow87-97dBA–portablesaw-105dBA–airwrench-107dBA–arcwelder-116dBACommunicationInNoisyEnvironments•Hardtohearsomeonetalkinginnoisyenvironments–thespeakerneedstobelouderthanbackgroundnoise•Radiosorcellphoneswillneedtobeturnedup–ifyouhaveahearingloss,itwillbehardertodistinguishspeechinthisenvironmentHowDoYouKnowYouAreExposedtoDamagingNoise•Feeltheneedtoshoutinordertobeheard3feetaway–soundlevelsprobablyapproaching85dBA•Ifimmediatelyafteraperiodofhighnoiseexposure–ringing,buzzingorwhistlingisnoticed•EquipmentistaggedormarkedasnoisehazardousHowMuchNoiseCanYouBeExposedTo?•OSHArules–90dBAaveragedoveran8hrshift•requirestheuseofPPEorothercontrolstoreduceyourexposure•ea...