Developed by Karen Hsi, UCOP EH&S Student Intern

 Hazardous noise exposures occur On the job…And off the job…

 Sound Level Meter - Instant reading › Quest 2200 › Sound level range from 30 to 140 decibels (dB)

 Temporary damage to sensorineural system – temporary threshold shift (TTS)  Permanent threshold shift (PTS) is noise induced hearing loss  Loss of communication  Physiological effects

 Causes no pain  Causes no visible trauma  Leaves no visible scars  Is unnoticeable in its earliest stages  Accumulates with each over-exposure  Takes years to diagnose Is permanent and 100% preventable

 Continuous Noise - 85 decibel, 8 hour time-weighted average (TWA)- Action Level ~Hearing conservation programs ~Training ~Annual audiometric examinations - 90 decibel, 8 hour TWA- Permissible Exposure Level ~Wear Earplugs

 If you must shout to be understood over the background noise when standing about one arm-length away from somebody, that background noise is potentially hazardous.

Permissible Exposure Limits

 Sound waves cause the eardrum to vibrate  Bones in middle ear transmit vibrations to cochlea  Receptors (hair cells) in cochlea convert vibrations to electrical energy  Brain interprets these electrical impulses as sound

 Nerve cells in the cochlea are tuned to specific frequencies  Base of the cochlea is sensitive to high frequency sounds  Tip of the cochlea is sensitive to low frequency sounds

Conductive  Caused by damage to or a malfunction of the outer and middle ear  Some causes › Excessive ear wax › Fluid in the ear › A torn eardrum › Colds  Usually hearing is restored once the cause is diagnosed and treated Sensory  Caused by damage to or a malfunction of the inner ear, auditory nerve, or the brain  Causes of sensory hearing loss › Aging, Damage to fetus, Hereditary, Noise, Disease, Injury, Drugs  Cannot be corrected medically or surgically  Hearing loss in the workplace is typically a sensory hearing loss

K P SH S TH T F CH H

 Imagine you are at a classical concert.. but you are experiencing progressive hearing loss during it. Listen to the difference! Imagine you are at a classical concert.. but you are experiencing progressive hearing loss during it. Listen to the difference!

 Indoor (Office Environment) › Office Background Noise–45 to 60 decibels › Elevator-55 to 65 decibels › Normal Conversation-60 to 65 decibels › Copying Machine-65 to 70 decibels  Outdoors (Street) › Street Background Noise– 65 to 75 decibels › Trucks, Buses Driving By-75 to 80 decibels  All noise levels found are within the Cal/OSHA permissible exposure limits

 Dr. Dean Garstecki, audiologist from Northwestern University, suggests that i-Pod users take precautions  Hearing loss found in younger people that is normally found in aging adults › Listening to music at 110 to 120 decibel range  Earbuds can boost sound signal by 6-9 decibels  Follow the 60% volume/60 minute rule

 Wear Noise- Cancelling Headphones  Helps to cancel out background noise and prevents listeners from cranking up the volume on their i-pods/mp3 players.  Also recommends use of older style, larger headphones that rest over the ear opening.

 UC Site Visits › Construction & Shops- Machinery, Backhoe, Tools, Jackhammers, etc. › Power Plants  Travel – Small Aircraft  Personal Activities/Hobbies › Gardening – Lawn Mower, Hedge Trimmer › Carpentry/Tools, Shooting Range,  Wear earplugs or earmuff to protect your hearing!!

Hearing Loss Due To Noise Exposure Is … Painless Permanent Progressive … and very PREVENTABLE !