NOISE AND ACOUSTICS

3. NOISE AND ACOUSTICS Hazardous noise exposures occur and off the job. on the job ..…

4. NOISE AND ACOUSTICS Noise-Induced Hearing Loss • 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

5. NOISE AND ACOUSTICS

6. NOISE AND ACOUSTICS How do I know if the noise levels are hazardous? If you must shout to be understood over the background noise when standing about one arm-length away from somebody, that background noise is hazardous.

7. NOISE AND ACOUSTICSTime-Weighted Average Permissible Exposure Limits

8. OSHA STANDARDTime-Weighted Average Permissible Exposure Limits

10. HOW WE HEAR • 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

11. HOW WE HEAR • 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

12. HOW WE HEAR • 17-year old girl • Low noise exposure • Normal cochlea • Receptors intact • 76-year old man • Low noise exposure • Fewer receptors but still intact • 59-year old man • High noise exposure • Damaged cochlea • Receptors destroyed

13. CH P S K H TH T F SH HOW WE HEAR High-frequency High-frequency sounds of speech

15. COMFORT COMFORT COMPATIBILITY WITH OTHER PPE COMPATIBILITY WITH OTHER PPE NOISE REDUCTION NOISE REDUCTION The Best Hearing Protection SIZE CLEANLINESS SIZE CLEANLINESS SPECIAL JOB REQUIREMENTS SPECIAL JOB REQUIREMENTS COMMUNICATION NEEDS COMMUNICATION NEEDS HPD SELECTION

16. “Hearing protectors are uncomfortable.” “I already lost some of my hearing, so why should I wear them?” “I don’t need them, I am used to the noise.” “Won’t I get an ear infection?” “Can I hurt my eardrums if I insert a plug to deeply.” “My machine sounds different.” “I can always get a hearing aid.” “I can’t hear my co-workers if I wear them.” HPD SELECTIONCommon Objections to Wearing HPDs

18. FITTING TIPSFind the Right Size Maximum protection is only accomplished when an earplug acoustically seals in the ear canal. No earplug fits all ear canals, so manufacturers have responded with a variety of sizes. It is important to find your right size to obtain an acoustic seal

19. 1. Rollentire earplug into a crease-free cylinder 2. Pull Backpinna by reaching over head with free hand, gently pull top of ear up and out 3. Insertearplug well into ear canal and hold until it fully expands FITTING TIPSROLL-DOWN FOAM

21. FITTING TIPSVisual Check for Foam Earplugs If properly fitted, the end of the earplugs should not extend beyond the tragus (flap of the ear canal).

23. Reach over head with free hand, pull ear up and back and insert earplug well inside ear canal. 2. Earplugsshould be inserted as shown in these drawings. Stop pushing earplug when finger touches the ear. 3. If properlyfitted, the end of the earplugs should not be visible to someone looking at you from the front. NO-ROLL FOAM EARPLUGS

24. 2. Insert earplug so all flanges are well inside the ear canal. • While holding the stem, reach hand overhead and gently pull top of ear up and back. 3. If properly fitted, only the stem of the earplugs should be visible to someone looking at you from the front. MULTIPLE-USE EARPLUGS

25. Visual Check - The earplug should sit well inside the ear canal and not stick out. EARPLUGS (ALL) 2. Acoustical Check - Cup hands over ears and release. Earplugs should block enough noise so that covering your ears with hands should not result in a significant noise difference.

26. Place earcups over eachouter ear 2. Adjust the headband by sliding the headband up or down at the attachment buttons 3. The ear cushions should seal firmly against the head EARMUFF INSTRUCTIONS

27. EARMUFF INSTRUCTIONS – DON’TS For best results, remove all hair from underneath earcup. Ensure that the earcup creates a seal and covers the ear completely.

29. PRODUCTSTypes of Hearing Protectors Earplugs • Single-Use • Multiple-Use • Detectable Banded Protectors • Banded Earplugs • Canal Caps Earmuffs • Standard (Headband) • Cap-Mounted • Electronic • Special Application

30. PROS AND CONS OF HPDs – EARPLUGS • PRO • Comfortable for extended use • Disposable earplugs available • Cooler in hot/humid environments • CON • Attenuation highly dependent upon good fit • Hygiene issues in dirty environments

31. CARE & MAINTENANCE OF HPDs – EARPLUGS • Dispose of single-use earplugs daily • Clean multiple-use earplugs with mild soap and water, dry thoroughly • Inspect multiple-use earplugs for dirt, cracks or hardness, replace if damaged

32. PROS AND CONS OF HPDs – BANDED EARPLUGS • Clean and replace pods regularly

33. CARE & MAINTENANCE OF HPDs – BANDED EARPLUGS • PRO • Very convenient for intermittent noise • Readily available around neck when not in use • CON • Lower attenuation than most earplugs • Some noise transmission through band

34. PROS AND CONS OF HPDs – EARMUFFS • PRO • Easy to get proper fit • Good for intermittent noise • Radio & electronic options • CON • Can feel hot/heavy with extended wear • Compatibility with other PPE?

35. CARE & MAINTENANCE OF HPDs – EARMUFFS • Clean ear cushions and headband regularly with mild soap and water • Replace ear cushionsand foam inserts every 6 months with normal wear, more often with heavy use or under humid/extreme conditions

36. Selecting Appropriate Hearing Protection • EHS will assist in selecting appropriate hearing protection. • Some high noise areas may require both ear plugs and ear muffs. • EHS has a noise dosimeter and is able to provide noise monitoring for individuals or areas of concern.

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

38. University of Michigan – Flint Roles & Responsibilities • Employer • Administer Hearing Protection Program • Provide appropriate hearing protection for employees • Provide annual hearing conservation training • Arrange for annual audiograms for employees • Keep records • Employee • Wear provided hearing protection in required areas or while performing tasks that produce high noise levels • Follow fitting instructions • Properly store & care for re-usable hearing protection. • Inspect re-usable hearing protection prior to use.

39. What is a Standard Threshold Shift? • STS is defined by OSHA/MIOSHA as average of 10 dbA or greater increased hearing threshold in 2,000, 3,000 and 4,000 Hz in one or both ears. • STS’s are a recordable injury under OSHA. However, in Michigan, a STS is not a recordable injury on the OSHA/MIOSHA unless the hearing thresholds have increased on an average of 25 dBA.

40. When an Employee has a Standard Threshold Shift (STS) • If an employee’s annual audiogram indicates a Standard Threshold Shift • The University’s medical provider notifies the employee and EHS. • The employee has 30 days to return to the clinic for a second audiogram to verify or refute the first one. • If the second audiogram verifies a STS, then this audiogram becomes the new baseline. • Work Connections is notified of verified STSs. • Per UM hearing conservation guidelines, the employee is notified via e-mail and needs to meet with EHS for education on hearing protection and conservation. • Employee signs letter stating they understand that they have a STS and have received applicable education and training.

41. University of Michigan Hearing Conservation Guidelines-Training & Education • STS and audiometric zero • recognizing noisy environments • noise exposure on and off the job • methods used to control and reduce noise exposure • properly selecting and fitting hearing protection • monitoring of workplace noise levels