Listen Up! Written by: Christy Bryan, Amanda Stephens & Dr. Frank Flanders Art by: Randy Glance & Mark Smith Reviewed by: Janet Ehlers of the National Institute for Occupational Safety & Health Go To: Test Questions Georgia CTAE Resource Network Revised April 2010 Note to Teacher: See ‘Notes’ section of the PowerPoint for additional information. Hearing Loss Prevention

Enduring Understanding Preventing hearing loss is of vital importance on the job as well as in everyday life. Permanent hearing loss can occur much easier than most people realize. Once hearing is damaged, it is damaged forever!

Essential Questions What sounds and sound levels may damage hearing? How can hearing loss be prevented? What is the proper use of hearing protection devices? How could hearing loss impact you in the future? How can sound be measured?

Measuring Sound Levels A decibel (dB) is the unit used to measure sound levels. A dB measures how loud sounds are and how the sounds will affect hearing. The higher the dB level, the louder the sound.

Activity I Instructions: Rank the following sounds from 1 to 8 with 1 being the sound least damaging to the ear and 8 being the most damaging to the ear. Check your answers on the next slide. Rock band1. ____________ Hand drill2. ____________ Squealing pig3. ____________ Gunshot4. ____________ Firecracker5. ____________ Circular saw6. ____________ Chainsaw7. ____________ Normal conversation8. ____________

Source: “Have You Heard? Hearing Loss Caused by Farm Noise is Preventable” Produced by Department of Health and Human Services, CDC, and NIOSH Return to Test Answers

Activity II Instructions: Rank the following sounds from 1 to 8 with 1 being the sound least damaging to the ear and 8 being the most damaging to the ear. Check your answers on the next slide. Chop saw1. ____________ Circular Saw2. ____________ Hand drill3. ____________ Orbital sander4. ____________ Miter saw5. ____________ Router6. ____________ Chainsaw7. ____________ Hammer drill8. ____________

Source: “Have You Heard? Hearing Loss Caused by Farm Noise is Preventable” Produced by Department of Health and Human Services, CDC, and NIOSH Return to Test Answers

Length of Exposure Long or repeated exposure to sounds at or above 85 decibels can cause hearing loss. The louder the sound, the shorter the time period before noise induced hearing loss can occur. Source: “They’re Your Ears Protect Them- Hearing Loss Caused by Farm Noise is Preventable” Produced by Department of Health and Human Services, CDC, and NIOSH

Hearing Loss Facts Hearing loss can be temporary or permanent. Hearing loss can occur at any age. Nothing can restore permanent hearing loss. Once it’s gone, it’s gone! All types of equipment and tools can cause hearing loss. When hair cells in the ear are damaged they do not grow back--unless you’re a reptile!

Parts of the Ear Source: National Institute of Health

Auditory Nerve The auditory nerve connects the inner ear to the brain. It transports information from the cochlea to the brain.

Cochlea Source: National Institute of Health The Cochlea is the part of the inner ear that is shaped like a snail. The inner ear is lined with hair cells that are too tiny to be seen without a microscope. They are called stereocilia. There are 18,000 hair cells per cochlea. All 18,000 hair cells would fit on the head of a pin.

Undamaged Stereocilia Source: National Institute of Health Stereocilia Are: Fingerlike projections They rock back and forth with the sound waves. They transmit messages to the brain, which is how a person hears sound.

Damaged Stereocilia Source: National Institute of Health The stronger the sound waves the greater damage inflicted upon the ear. Once damaged, stereocilia can not be repaired. Damaged stereocilia causes hearing loss.

How can hearing be protected? 1.Turn down the volume of: MP3 players Radio/Stereo systems TV 2.Walk away from loud noise 3.Wear a hearing protection device 4. Control the noise by adjusting equipment, blocking or deflecting the noise, etc.

Hearing Loss Prevention Devices Earmuffs Earplugs- Formable Earplugs- Premolded Canal Caps

Ear Plugs Ear plugs come in different sizes and should fit snugly into the outer ear canal (auditory canal). For people who need them frequently, such as people who are regularly exposed to job-related noise, they can be custom-made for a better fit. You also can buy disposable ear plugs.

Application of Formable Earplugs 1. Roll 2. Reach 3. Insert 4. Hold Proper way to insert earplugs

Inserting An Earplug If the earplug looks similar to this then it is: Source: “ Tips and tools for fitting and using foam earplugs” by Elliott Berger

Ear Muffs Ear muffs cover both ears entirely. When they fit properly and are held in place by a headband, they form an air-seal that reduces the volume of sound entering the ears.

Canal Caps Canal caps are worn under the chin not over the head. Canal caps are convenient: they can be worn around the neck when not in use.

Check the Noise Reduction Rating When purchasing hearing protection, always be sure to check the Noise Reduction Rating (NRR) number on the package. The NRR number is the measure, in dB, of noise reduction. The NRR can be twice as high as the protection you will actually get. Keep this in mind when selecting hearing protection.

If hearing protection is worn, but not worn correctly, damage to hearing may still occur. Be sure to read all instructions and warnings on the packaging. Follow all manufacturer’s instructions.

Activity Three: Purpose To demonstrate the permanent damage to hearing (stereocilia damage) caused by loud noises. Source:

Activity Three: Shake It, Break It 1.Place 3-5 pipe cleaners in one hand and at the bottom make a fist around them as shown. The pipe cleaners represent the hair cells in your inner ear (stereocilia) that may be damaged and cause hearing loss. Source:

Activity Three Continued… 2. Gently move your hand so that the pipe cleaners sway slightly. This represents low to medium noises and music. 3. Move your hand a little faster so that the pipe cleaners sway more without bending. This represents border-line noises or music. Source:

Activity Three Continued… 4.Move the pipe cleaners vigorously so that they sway forcefully and bend over. The more violent you shake the better. This represents the effect of loud noises or music. Source:

Activity Three Continued… 5.Try to straighten the pipe cleaners in any manner you prefer. Try to make them look like they did originally. 6.You cannot make them as straight as they once were. This is what permanent hearing loss looks like! Source:

Myth and Fact Myth: A person can’t hear people around them or the machine or tool they’re using while wearing earplugs. Fact: Earplugs block background sound which may allow you to better hear people around you and the machine or tool.

Myth and Fact Myth: Hearing aids correct hearing just like glasses correct vision. Fact: Hearing aids will not fully restore lost hearing.

Myth and Fact Myth: The insurance company will pay for a hearing aid. Fact: Many insurance companies will not pay for hearing aids. Fact: Even the best hearing aids, which range from $3,000-$6,000, do not fully restore hearing.

Review Questions What happened to your model of the inner ear (stereocilia) in Activity One? Do you think doctors can repair the tiny hair cells (stereocilia)? Name three sounds that are loud enough to damage the ear. What can you use to protect your hearing? What are some activities in your everyday life that may damage your hearing?

Test Questions 1.At what dB level does noise become harmful to hearing? 2.How can you restore your hearing once it is lost? 3.What does the NRR number tell you on hearing protection product packaging? 4.Name three tools or pieces of equipment that can cause hearing loss. 5.What part of the ear is damaged during hearing loss?

Test Questions Continued… 6.At what decibel level does a normal conversation occur? 7.True or False: A farmer drives a tractor at 90dB for 30 years, without hearing protection, this will cause no hearing loss. 8.Can a hearing aid completely restore hearing once it is lost? 9.Name three devices that can prevent hearing loss. 10. Should an ear plug be rolled or folded before it is inserted into the ear?

Test Answers 1.85 dB 2.You cannot restore your hearing once it is lost. Hearing loss is permanent! 3.The Noise Reduction Rating is the measure, in dB, of noise reduction. 4.Refer to chart 1 or chart 2: some answers may include gunshot, tractor, firecrackers, chainsaw, hammer drill, etc.chart 1 chart 2 5.The “hair cells” or stereocilia are damaged.

Test Answers Continued… 6.A normal conversation occurs at 60 dB. 7.False. Even though the noise is only 5 dB higher than 85 dB, the continuous noise over a long period of time may cause hearing damage. 8.A hearing aid cannot fully restore hearing once it is lost. It simply amplifies the sounds through a microphone. 9.You can prevent hearing loss by wearing hearing protection devices, walking away from the noise, and turning the volume level down. 10.Three types of hearing protection devices are: ear plugs, ear muffs, and canal caps.