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:� TrafficTraffic

� Industrial equipment and toolsIndustrial equipment and tools

� MusicMusic

� Gunfire exercisesGunfire exercises

� VentilationVentilation

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

Noise Exposure Noise Exposure

Determined by:Determined by:� Duration of exposureDuration of exposure

� Type of noiseType of noise• ContinuousContinuous• ImpulseImpulse

� IntensityIntensity

� FrequencyFrequency

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 Has bones and ear drum which can rupture

from sudden high sound pressure levelsfrom sudden 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

FrequencyFrequency� Measured in hertz (Hz) or cycles per secondMeasured in hertz (Hz) or cycles per second

� Determines how high or low the pitch soundDetermines how high or low the pitch sound

IntensityIntensity� Measured 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 on� Pitch of the soundPitch of the sound

� Age of the individualAge of the individual

� Distance from noise sourceDistance from noise source

� Previous noise exposuresPrevious noise exposures

� Environment (surroundings)Environment (surroundings)

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

levelslevels� 20 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 Engineering controls to reduce the

hazardhazard Posting of noise hazardous areasPosting of noise hazardous areas Providing hearing protection to Providing hearing protection to

personnelpersonnel 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 exposure� DOD = 85 dBDOD = 85 dB

� OSHA = 90 dBOSHA = 90 dB

� Impact (Impulse) noise limit = 140 dBImpact (Impulse) noise limit = 140 dB

84 dB or less--OK for personnel 8 hours 84 dB or less--OK for personnel 8 hours a day, five days a week with no ill effects. a 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 have� Continuous noise >84 dBContinuous noise >84 dB

� Impact noise >140 dBImpact noise >140 dB

Survey documents retained onboardSurvey documents retained onboard� Readings repeated after overhaul or if new Readings repeated after overhaul or if new

equipment added/changedequipment added/changed

� Readings 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 of� New constructionNew construction

� OverhaulOverhaul

� SHIPALTSHIPALT

� IMAIMA

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

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

design or imposing controlsdesign or imposing controls� Damping material or sound curtains around Damping material or sound curtains around

equipmentequipment

� Acoustical tiles for classroomsAcoustical tiles for classrooms

� Rubber insulating pads at metal-to-metal Rubber insulating pads at metal-to-metal interfaceinterface

� Moving 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 Use Yellow and Black signs to mark

hazardshazards� Large signs for entire areasLarge signs for entire areas

� Small stickers for individual equipmentSmall stickers for individual equipment

Post areas as DOUBLE Hearing Post areas as DOUBLE Hearing Protection Required if sound levels Protection Required if sound levels >104dB>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 muffs� Mechanically block noise from earMechanically block noise from ear

� Rated 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 canal

� Fitted/Flanged types issued by MedicalFitted/Flanged types issued by Medical

� Disposable foam plugs don’t require fitting--Disposable foam plugs don’t require fitting--also have highest NRR (about 30dB)also have highest NRR (about 30dB)

Ear muffsEar muffs� Fit over outer earFit over outer ear

� Have NRR of 24-28 dBHave NRR of 24-28 dB

� Ear caps--like plugs with a head band--NRR Ear caps--like plugs with a head band--NRR of about 22 dBof about 22 dB

Personal ProtectionPersonal Protection

Double protectionDouble protection� Required when continuous sound levels Required when continuous sound levels

>104dB>104dB

� Use 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 condition� Dirty plugs may cause infectionsDirty plugs may cause infections

� Muffs with hardened seals DO NOT protectMuffs with hardened seals DO NOT protect

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

all personnel working in noise hazardous all personnel working in noise hazardous areasareas

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 Termination audiograms given to personnel when leaving the servicepersonnel when leaving the service