WhatdoformerAmericanpresidentBillClintonandrockmusicianPeteTownshendhaveincommon.'?Bothmenhavehearingdamagefromexposure(暴露,接触)toloudmusicandbothnowwearhearingaids(助听器)asaresult.AsateenagerClintonplayedsaxophoneinaband.TownshendwhohasthemoreseverehearinglosswasaguitaristforabandcalledtheWho.Heisoneofthefirstrockmusicianstocallthepublic'sattentiontotheproblemofhearinglossfromexposuretoloudmusic.
Temporary(暂时)hearinglosscanhappenafteronly15minutesoflisteningtoloudmusic.Oneearlywarningsigniswhenyourearsbegintofeelwarmwhileyoulistentomusicatarockconcertorthroughheadphones.Onelateristhatanunusualsoundoraringingissometimesproducedinyourheadaftertheconcert.
"Whathappensisthatthehaircellsintheinnereararedamagedbutthey'renotdead"saysphysicianandearspecialistDr.SamLevine.AccordingtoDr.Levineifyouavoidfurtherexposuretoloudnoiseit'spossibletoreconditionthecells(细胞)somewhat.Howeverheadds"Eventuallyoveralongperiodoftimehaircellsarepermanentlydamaged."Andthisisnosmallproblem.
Whatsoundlevelisdangerous?AccordingtoDr.Levineregularexposuretonoiseabove85decibels(分贝)isconsidereddangerous.Thechartbelowoffersacomparisonofdecibellevelstocertainsounds.Here'sanothermeasurementyoucanuse.Ifyou'reatarockconcertandthemusicissoloudthatyouhavetoshouttomakeyourselfheardyou'reatriskforhearingloss.That'swhenwearingprotectivedevicessuchasearplugsbecomescritical.
Thefactsareprettyfrightening.Butarerockbandsturningdownthevolume.'?Mostaren't."Rockmusicissupposedtobeloud"saysdrummerAndrewSather."Iwouldn'thaveitanyotherway.Andneitherwouldtherealfansofrock."
ContinuedexposuretoloudmusicandthefailuretowearearplugscanleadtodeafnessaccordingtoDr.Levine.Hestates"There'snocureforhearingloss.Yourearsaretryingtotellyousomething.Thatringingisthescreamofyourhaircellsdying.Eachtimethathappensmoreandmoredamageisdone."
LevelsofCommonNoises
Normalconversation &