EAR SAFETY

THE EAR

OUTER EAR MIDDLE EAR INNER EAROUTER EAR - MIDDLE EAR - INNER EAR

AUDITORYNERVE

HAMMERANVIL

NERVE

ANVILSTIRRUP

COCHLEA

EARCANAL

EARDRUM

EUSTACHIANTUBE

Noise Basics

Th t f t th t d t i h h d• The two factors that determine how hazardous noise is are:– Intensity (Loudness) measured in dBA– Time of Exposure measured in Hours and Minutes

• The louder the noise, the more hazardous it is. Also, the longer the exposure time, the more , g p ,hazardous the noise is.

• A “Noise Dose” combines both loudness andA Noise Dose combines both loudness and time and is a convenient way of describing the relative hazard of the noiserelative hazard of the noise.

Noise BasicsLoudness is measured using a logarithmic scale. This means that a 10 decibel increase does not simply add 10 to the previous level. It multipliesth i l l b 10the previous level by 10.

Threshold of Hearing 0 dBAQuiet Room 45 dBAConversation 55 dBA = 45 dBA x 10Car (50 mph at 50 ft) 65 dBA = 45 dBA x 100( p )End Loader (In Good Cab) 75 dBA = 45 dBA x 1,000Haul Truck (In Good Cab) 85 dBA = 45 dBA x 10,000Crusher 95 dBA = 45 dBA x 100 000Crusher 95 dBA 45 dBA x 100,000Old Dozer (No Cab) 105 dBA = 45 dBA x 1,000,000Air Track Drill (No Controls) 115 dBA = 45 dBA x 10,000,000

115 dBA has 10 million times more sound energy 10 million times more sound energy than 45 dBA and iscapable of causing 10 million times more damage to hearing.

Human Hearing Ranges

Noise destroys your hearing little by little. Exposure to noise occurs on and off the job. Your ears typically “recover” from exposures torecover from exposures to low level noises. However, permanent damage may occur from even a single exposure to very loud noises.g p y

• 20 Hz (low rumble) to 20,000 Hz (whine)• Speech Between 500 Hz to 2000 Hz• Average Hearing Loss at 4000 Hz and up• 0 dB (just audible) to 140 dB (causes pain)• 80 dB(A) 8 hour TWA will affect some• 100 dB(A) 8 hour TWA will affect all

Sources of Noise

• Work related noise from machinery, grinding, drilling and vibrating tools etc.

• Pumps, compressors, turbines. • Blast Noise from firearms and bombs. • Pleasure related musical noise in discos and earphones. • Environmental noise pollution from generators, car horns,

aircrafts, ships etc. • House hold equipment like kitchen blender, lawn mower etc.

FACTORS AFFECTING HEARING

WORK SOURCES & FACTORS AFFECTING HEARING:WORK SOURCES & FACTORS AFFECTING HEARING:

• Age• PitchPitch• Loudness• Surroundings• Type of machinesyp• Position of source• Length of exposure• Previous ear trouble• Distance from source• Think about your personal work habits!

Hearing LossgTHE COCHLEA AND THE INNER EAR

• A fluid filled sound reception chamber• A fluid filled sound reception chamber• Contains thousands of tiny hair cells• The cells respond to sound waves made in the fluid• The cells pass the sensation on to the auditory nerve

SENSORI-NEURAL HEARING LOSS

• Noise induced hearing loss• Noise-induced hearing loss• Damages the hair cells or auditory nerves• If the noise is stopped hair cells can bounce back• Damage can be temporaryg p y

SENSORI-NEURAL HEARING LOSS

• If the noise continues hair cells can’t bounce backIf the noise continues hair cells can t bounce back• Damage can be permanent

SYMPTOMS OF HEARING LOSS

• Constant ringing in the ear (tinnitus) • Difficulty hearing soft sounds, such as a

child’s voicechild s voice • Complaints from others that you are talking

too loudly or shouting unnecessarilytoo loudly or shouting unnecessarily • Difficulty in separating speech from

b k d ibackground noise • Having to turn up the volume on TVs or

radios

Engineering controlsg g

• Isolate noisy machinery in a separate area• Place machinery on rubber mountings• Use sound-absorbing acoustical tilesg• Arrange work schedules to reduce employee

exposure to noise• Inform supervisors of unpleasant/unacceptable noise

levels

3a

HEARING PROTECTION

As with all personal protection – Ear protectionAs with all personal protection Ear protection

is the last line in the hierarchy of control

TYPES OF HEARING PROTECTION DEVICES

• Ear Muffs (Circumaural)• Ear Muffs (Circumaural)

• Semi-Inserts (Semi-Aural)

• Inserts (Aural)

CONCLUSIONHEARING LOSS HAPPENS!

Noise induced hearing loss is 100% preventable

Your hearing health starts with YOU while at work or home

If YOU don’t protect it YOU will lose it