Hearing Conservation Hearing Conservation ProgramProgram

A. BackgroundA. Background

NoiseNoise Any unwanted sound--created by many Any unwanted sound--created by many

different sources:different sources:TrafficTrafficIndustrial equipment and toolsIndustrial equipment and toolsMusicMusicGunfire exercisesGunfire exercisesVentilationVentilation

Excessive noise--over time and certain levels--Excessive noise--over time and certain levels--can cause hearing losscan cause hearing loss

Noise Exposure Noise Exposure

Determined by:Determined by:Duration of exposureDuration of exposureType of noiseType of noise

• ContinuousContinuous

• ImpulseImpulse

IntensityIntensityFrequencyFrequency

Causes of Hearing LossCauses of Hearing Loss

AgeAge Disease (Middle or Inner Ear)Disease (Middle or Inner Ear) TraumaTrauma DrugsDrugs Noise exposureNoise exposure

B. How Hearing Loss OccursB. How Hearing Loss Occurs

Damage to the EarDamage to the Ear Outer ear--Outer ear--

Catches dirt and particles in the canal that Catches dirt and particles in the canal that contains cerumen or waxcontains cerumen or wax

Middle ear--Middle ear--Has bones and ear drum which can rupture from Has bones and ear drum which can rupture from

sudden high sound pressure levelssudden high sound pressure levels

Inner ear--Inner ear--Has cochlea with tiny hair cells connected to Has cochlea with tiny hair cells connected to

nerves. Damage is irreversiblenerves. Damage is irreversible

Cochlea

Middle ear

C. Measuring SoundC. Measuring Sound

TerminologyTerminology

FrequencyFrequencyMeasured in hertz (Hz) or cycles per secondMeasured in hertz (Hz) or cycles per secondDetermines how high or low the pitch soundDetermines how high or low the pitch sound

IntensityIntensityMeasured in decibels (dB)Measured in decibels (dB)Determines how “loud” a noise soundsDetermines how “loud” a noise sounds

Other InformationOther Information

Ability to hear well depends onAbility to hear well depends onPitch of the soundPitch of the soundAge of the individualAge of the individualDistance from noise sourceDistance from noise sourcePrevious noise exposuresPrevious noise exposuresEnvironment (surroundings)Environment (surroundings)

Other InformationOther Information Sound level meters used to measure noise Sound level meters used to measure noise

levelslevels20 Decibels (dB)--faint sound (like a quiet 20 Decibels (dB)--faint sound (like a quiet

bedroom)bedroom)150 Decibels (dB)--F-14 at takeoff on flight 150 Decibels (dB)--F-14 at takeoff on flight

deckdeck

Navy Industrial Hygiene Officers (IHO) Navy Industrial Hygiene Officers (IHO) conduct noise surveysconduct noise surveys

D. Navy Hearing Conservation D. Navy Hearing Conservation ProgramProgram

Program ObjectiveProgram Objective The objective of the Hearing The objective of the Hearing

Conservation Program is to prevent Conservation Program is to prevent hearing loss as a result of exposure to hearing loss as a result of exposure to hazardous noise.hazardous noise.

How would How would YOU YOU like to own this?like to own this?

Program ElementsProgram Elements Identifying noise hazardous areasIdentifying noise hazardous areas Engineering controls to reduce the hazardEngineering controls to reduce the hazard Posting of noise hazardous areasPosting of noise hazardous areas Providing hearing protection to personnelProviding hearing protection to personnel Medical monitoring (audiograms)Medical monitoring (audiograms) Education and trainingEducation and training

E. The Program ElementsE. The Program Elements

Identifying Noise Hazardous Identifying Noise Hazardous AreasAreas

Limits for continuous noise exposureLimits for continuous noise exposureDOD = 85 dBDOD = 85 dBOSHA = 90 dBOSHA = 90 dBImpact (Impulse) noise limit = 140 dBImpact (Impulse) noise limit = 140 dB

84 dB or less--OK for personnel 8 hours a 84 dB or less--OK for personnel 8 hours a day, five days a week with no ill effects. day, five days a week with no ill effects.

Above 84 dB--Navy considers noise Above 84 dB--Navy considers noise hazardoushazardous

Identifying Noise Hazardous Identifying Noise Hazardous AreasAreas

Sound level surveys conducted to Sound level surveys conducted to determine which spaces routinely havedetermine which spaces routinely haveContinuous noise >84 dBContinuous noise >84 dBImpact noise >140 dBImpact noise >140 dB

Survey documents retained onboardSurvey documents retained onboardReadings repeated after overhaul or if new Readings repeated after overhaul or if new

equipment added/changedequipment added/changedReadings reviewed every 2 years as part of Readings reviewed every 2 years as part of

IH survey IH survey

Engineering ControlsEngineering Controls

Accomplished as part ofAccomplished as part ofNew constructionNew constructionOverhaulOverhaulSHIPALTSHIPALTIMAIMA

Applied to submarines to reduce Applied to submarines to reduce waterborne noisewaterborne noise

Engineering ControlsEngineering Controls Noise can be decreased by changes in design Noise can be decreased by changes in design

or imposing controlsor imposing controlsDamping material or sound curtains around Damping material or sound curtains around

equipmentequipmentAcoustical tiles for classroomsAcoustical tiles for classroomsRubber insulating pads at metal-to-metal interfaceRubber insulating pads at metal-to-metal interfaceMoving noise equipment to isolated locationMoving noise equipment to isolated location

Engineering controls must be considered Engineering controls must be considered FIRSTFIRST, prior to resorting to PPE, prior to resorting to PPE

Posting Noise Hazard SignsPosting Noise Hazard Signs Used when engineering controls do not Used when engineering controls do not

work, or are not feasiblework, or are not feasible Use Yellow and Black signs to mark hazardsUse Yellow and Black signs to mark hazards

Large signs for entire areasLarge signs for entire areasSmall stickers for individual equipmentSmall stickers for individual equipment

Post areas as DOUBLE Hearing Protection Post areas as DOUBLE Hearing Protection Required if sound levels >104dBRequired if sound levels >104dB

Personal ProtectionPersonal Protection

Used as last resort--when exposures Used as last resort--when exposures cannot be controlled by any other meanscannot be controlled by any other means

Ear plugs and muffsEar plugs and muffsMechanically block noise from earMechanically block noise from earRated for specific Noise Reduction Rating Rated for specific Noise Reduction Rating

(NRR)--reduce decibel levels reaching the (NRR)--reduce decibel levels reaching the ear by the number listed on the packageear by the number listed on the package

Personal ProtectionPersonal Protection Ear plugsEar plugs

Fit into ear canalFit into ear canalFitted/Flanged types issued by MedicalFitted/Flanged types issued by MedicalDisposable foam plugs don’t require fitting--also have Disposable foam plugs don’t require fitting--also have

highest NRR (about 30dB)highest NRR (about 30dB)

Ear muffsEar muffsFit over outer earFit over outer earHave NRR of 24-28 dBHave NRR of 24-28 dBEar caps--like plugs with a head band--NRR of about Ear caps--like plugs with a head band--NRR of about

22 dB22 dB

Personal ProtectionPersonal Protection

Double protectionDouble protectionRequired when continuous sound levels Required when continuous sound levels

>104dB>104dBUse combination of ear plugs and ear muffsUse combination of ear plugs and ear muffs

Must be kept clean and in good conditionMust be kept clean and in good conditionDirty plugs may cause infectionsDirty plugs may cause infectionsMuffs with hardened seals DO NOT protectMuffs with hardened seals DO NOT protect

Medical MonitoringMedical Monitoring Baseline and routine testing required for all Baseline and routine testing required for all

personnel working in noise hazardous areaspersonnel working in noise hazardous areas All naval personnel given baseline All naval personnel given baseline

audiogram when entering the serviceaudiogram when entering the service Annual audiograms given to personnel Annual audiograms given to personnel

assigned work in noise hazardous areasassigned work in noise hazardous areas Termination audiograms given to personnel Termination audiograms given to personnel

when leaving the servicewhen leaving the service