Syracuse University

Hearing Conservation Program Training

John

Rossiter, Safety Department

Introduction

   This training is designed to teach you about the purpose and benefits of a hearing conservation program. After completing the training, you should understand the following: The effects of noise on hearing The purpose of SU's Hearing Conservation Program The proper selection and use of hearing protection devices  The purpose of audiometric testing

How We Hear

Sound is measured by its:  frequency  intensity When we hear a sound this is what actually takes place:      

SOUND WAVES

enter the ear canal and cause the eardrum to vibrate.

VIBRATIONS

pass through 3 connected bones in the middle ear This motion

SETS FLUID MOVING

in the inner ear.

Moving fluid bends thousands of delicate hair-like cells which convert the vibrations into

NERVE IMPULSES

.

Nerve impulses are

CARRIED

to the brain by the auditory nerve In the brain, these impulses are

CONVERTED

into what we "hear" as sound.

How Noise Affects Health

  A

temporary hearing loss

can be caused by exposure to loud noise for a few hours. Fortunately, hearing is usually restored after a period of time away from noise.

A

permanent hearing loss

occurs after the ear has been continually exposed to excess noise and has gradually become unable to recover from temporary hearing loss.

There are warning signs that may be indicative of permanent hearing loss:  inability to hear high-pitched or soft sounds   trouble understanding conversation, or speech heard over the telephone ringing or roaring in the ears (called tinnitus)

Noise Levels

DECIBELS

85-90

EXPOSURE

Exposure over a length of time MAY cause hearing loss. Examples: subway, loud shout

EFFECTS

Most hearing loss happens over a period of time - weeks, months or years. No pain at this level of exposure.

90-100 Exposure over a length of time causes hearing loss. Examples: Power mower, air hammer, newspaper press At this level of exposure, the noise can be uncomfortable 100-130 Exposure over a short period of time causes hearing loss. Examples: riveter, compactor, rock concert Tinnitus (ringing in the ears) may occur after an exposure at this level. Discomfort threshold is 120 dB(A) 140+ A single exposure can cause hearing loss. Examples: jet taking off, shotgun Pain threshold.

Hearing Conservation Program

 A Hearing Conservation Program must include four basic parts: 

Noise Monitoring



Hearing Protection



Hearing Tests



Training

Noise Monitoring

 Area monitoring – noise meter  Personal monitoring – noise dosimeter

Hearing Protection Devices

There are three basic types of hearing protection devices: 

ear muffs



ear plugs



canal caps

Noise Reduction Rating ( indicates the degree to which that device reduces noise exposure.

NRR):

a number that

HPD - Ear Plugs

 Light weight  Can be worn without interference from eyeglasses, headgear, earrings or hair  Comfortable in hot/humid environments  Less expensive than ear muffs

Ear Plug Insertion

 Wash your hands.  Inspect the ear plugs.  Roll the plug between your fingers and thumb, making sure there are no wrinkles or creases in the plug.

 Reach one hand behind your head and pull your ear outward and upward to widen the auditory canal.

 Insert the plug well into the ear and hold it in place until it expands.

HPD - Ear Muffs

 Provide more consistent protection than plugs  One size fits most heads  Easy to put on and take off  Good for short jobs

Ear Muff Disadvantages

 heavier than ear plugs  may be uncomfortable in hot environments  eyeglass wearers may not get a good seal  expensive  resonate (vibrate) at lower sound frequencies (<400 Hz)

Wearing Ear Muffs

 Inspect for cracks, tears or other signs of wear.  Choose eyewear with thin temples so they don't interfere with the seal.

 Push your hair away from your ears.  Center the ear muffs over your head and make sure the seal is tight.  Adjust the headband so the ear muffs are resting comfortably on your head. The cups should be entirely cover your ears.

HPD - Canal Caps

 They DO NOT extend into the ear canal, only close the ear opening.

 They are NOT designed for continuous, long term wearing.

 They do not give you as much protection as ear plugs or ear muffs.

Ear Cap Insertion

 Wash your hands  Reach one hand behind your head and pull your ear outward and upward to widen the auditory canal.

 Insert the tip of the cap into the ear, firmly pushing and wiggling them into place

Audiometric Testing

 Audiometric Testing – Baseline – Annual retest A Standard Threshold Shift (

STS

) occurs when the hearing threshold has changed by an average of 10 decibels (dB) or more in either ear at 2000, 3000 or 4000 Hertz. If audiometric testing reveals that you have a STS, you will be notified.

It’s Your Hearing - Protect It!

 Attend annual training  Get an annual audiogram  Wear PPE if required  Avoid long term exposure to noise, both at home and at work