OSHA Occupational Noise 29 CFR 1910.95 Clark Safety & Loss Control

OSHA Occupational Noise 29 CFR 1910.95 Non-Occupational Hazardous Noise Noise Monitoring Noise Map (Area Monitoring) Noise Dose (Personal Monitoring) Table of Permissible Noise Exposure Limits Impulsive or Impact Noise Daily Allowable Exposure Times to Noise Affected Employees Noise Control Administrative Controls Engineering Controls Personal Protective Equipment Hearing Protection Device Noise Reduction Rating (NRR) Hearing Protection Use Employee Responsibility Management Responsibility Purpose of Hearing Protectors Different Types of Hearing Protectors Selection, Fitting, Use, and Care of Hearing Protectors Audiometric Testing What is an Audiogram Standard Threshold Shift Audiometric Test Requirements Training Record Keeping Proper Use of Hearing Protection Summary QUIZ Definition of Noise When is Noise Too Loud Hearing Loss From Noise Exposure Tinnitus From Noise Exposure Noise Permissible Exposure Limits Hearing Conservation Program Rule of Thumb Elements of Hearing Conservation Program HCP Flow Chart Sound Pressure Level Anatomy of the Human Ear How We Hear Sounds Healthy Cochlea Effects of Noise on Hearing Damaged Cochlea Symptoms of Overexposure to Noise Anatomy & Physiology of Healthy Ear Anatomy & Physiology of Damaged Ear How Hearing is Damaged Signs of Hearing Loss Types of Hearing Loss Noise Induced Hearing Loss Occupational / Non-Occ. Hearing Loss Statistics on Occupational Hearing Loss Effects of Age & Noise on Hearing Types of Noise Examples of Noisy Equipment Recognizing Occupational Hazardous Noise

Definition of Noise “Unwanted Sound”

Can You Imagine ? Not being able to: Being afflicted with: Hear what the other person is saying ? Listen to the sound of music ? Listen to the sound of nature ? Being afflicted with: Uncomfortable ringing in your ears ? Abnormal sounds that interfere with your sleep ?

When is Noise Too Loud ? Noise is measured in units called “decibels” or “dB” If two people 3 feet apart must shout to be heard, the background noise is too loud (above 85 decibels). Noise above 140 decibels causes pain and immediate hearing loss. “People with normal hearing usually must raise their voices to hear each other if background noise level is above 85 decibels. People with some hearing loss will have difficulty hearing at lower levels of background noise. An example of noise over 140 decibels is gunshots. Unprotected exposure to noise over 115 decibels greatly increases the risk of hearing loss.” 3

When is Noise Too Loud ?

When is Noise Too Loud ?

Hearing Loss From Noise Exposure Hearing loss from noise exposure is usually not noticed because it is so gradual. Usually a person loses the ability to hear higher pitches first. Often the first noticeable effect is difficulty in hearing speech. “Speech includes higher pitches such as in the letter “s”. People who have some hearing loss will often say “I can hear you talking, but I can’t understand you”. The difficulty in hearing speech is usually worse in a crowded room when many people are talking.” Other signs that a person is losing their hearing is that they will often turn up a TV or radio, or they may say they can’t hear birds singing anymore. Hearing aids only partially help people with severe hearing loss. 6

Tinnitus From Noise Exposure Exposure to high noise levels can also cause permanent ringing in the ear or “tinnitus” Tinnitus sufferers usually complain of constant whistling, squealing, roaring or buzzing in one or both ears. Severe tinnitus may disrupt sleep, reduce concentration & cause irritability and depression. “Tinnitus is difficult to treat. Many doctors will tell a person with tinnitus that “they just have to live with it” . There are several treatments that can provide some relief however, including certain drugs, masking devices worn in the ears, or other devices which help the brain ignore the sound. [More information on treatment on tinnitus can be obtained from the American Tinnitus Association in Portland, Oregon. Their phone number is 503-634-8978 or 503-248-9985.] 7

Noise Permissible Exposure Limits (PEL) Noise should not exceed 140 dB. Utilize administrative or engineering controls when sound levels exceed Noise Permissible Exposure Levels, e.g. 8 hours permitted duration per workday for 90 dB sound level. Provide hearing protectors if above controls fail to reduce sound levels within Permissible Exposure Levels (Table N-1). Impulsive or impact

Hearing Conservation Program (HCP) Implemented whenever employee noise exposures equal or exceed and 8-hour time-weighted average (TWA) of 85 dBa without attenuation from use of hearing protectors.

Rule of Thumb When you feel the need to shout in order to be heard 3 feet away, the noise levels are probably 85 dB or more and hearing protectors are recommended.

Elements of Hearing Conservation Program Noise Monitoring Hearing Protectors Audiometric Testing Evaluation of Audiogram Audiometric Test Requirements Audiometer Calibration Training Record Keeping

HCP Flow Chart Pre-employment Test Noise Map (area noise – sound level meter) Occupational Noise Exposure (personal noise – noise dosimeter) Noise Dose > 100% - noise control – engr. ctrl.; otherwise ppe < 100% - audiometric test Engr. Ctrl. / PPE – audiometric test Audiometric Test – noise induced hearing loss Yes – utilize noise control No – continue audiometric test Training Record Keeping

Sound Pressure Level Sound waves are energy produced by vibrating objects. The larynx vibrates to produce the voice. The vibrations create a pattern, which the ear translates into sound. As you double the distance from a noise source, the source loudness decreases by half. Strong vibrations from very loud noises can damage the ear.

Anatomy of the Human Ear

Anatomy of the Human Ear

How We Hear Sounds Sound waves enter the ear canal striking the eardrum. When eardrum vibrates, ossicles conducts vibrations to the cochlea. Tiny hair-like cells in cochlea respond to vibrations by generating nerve impulses. Brain interprets nerve impulses as sound.

How We Hear Sounds (cont) Note: Healthy hair cells are the key to good hearing. Although, some die off naturally as you age, many more are killed early, from unprotected exposure to hazardous noise.

The cilia ( sensory hairs) appear normal Healthy Cochlea The cilia ( sensory hairs) appear normal

Effects of Noise on Hearing Note: How quickly hearing loss takes place depends on the intensity of the noise, its duration, and how often the exposure occurs.

Loss of cilia as a result of Noise Damaged Cochlea Loss of cilia as a result of Noise

Symptoms of Overexposure to Noise Temporary Threshold Shift: muffled sound after noise exposure if continued overexposure, shift can worsen and become permanent resulting in untreatable damage to hearing Tinnitus: ringing in the head when trying to sleep at night if continued overexposure, ringing can become permanent, constant annoyance

Anatomy & Physiology of Healthy Ear

Anatomy & Physiology of Damaged Ear

How Hearing is Damaged Hair-like cells are flattened. You do not get used to noise; you gradually loose your hearing. Once haring is damaged, it cannot be repaired or replaced.

Anatomy & Physiology of Damaged Ear

Signs of Hearing Loss Difficulty hearing people speak. Inability to hear certain high-pitched or soft sounds. Noise or ringing in ears. Getting complaints that the radio or TV is too loud.

Types of Hearing Loss Conductive: Sensor neural : Mixed: Sound is not conducted from outer ear to inner ear Reduction in sound level Condition results from fluid in middle ear, foreign bodies, infection in ear canal, impacted ear wax, malformation of ear Sensor neural : Results from damage to the inner ear or nerve pathways from ear to brain Corrected through surgery Caused by birth injury, diseases, noise exposure, head trauma, aging Mixed: Hearing loss resulting from both conductive and sensor neural

Noise Induced Hearing Loss Noise induced hearing loss stems from exposure to loud noises: Constant exposure over a period of time Exposed to sound level over 140 dBA Tinnitus Age Induced Hearing loss: Exposure to high sound levels Hereditary Nerve damage Reduced neuronal response

Occupational / Non-Occ. Hearing Loss Occupational Hearing Loss: Results from constant exposure to sound levels above 85 dBA TWA Damage to hair cells in cochlea Non-Occupational Hearing Loss: Results from constant exposure to sound levels above 85 dBa TWA Results from damage to outer, middle, or inner ear, hereditary, to toxic drugs Damage to hair cells in cochlea, damage to nerve cells relaying sound message to brain, damage to structure of ear

Statistics on Occupational Hearing Loss Approximately 30 million Americans are exposed to high intensity noise in their workplace. One in 4 of these workers (or 7.5 million Americans) will develop permanent hearing loss.

Effects of Age & Noise on Hearing

Types of Noise Pitch Loudness Whisper 10 dB Street sound 70 dB Sander 85 dB Sporting Events 100 dB Mowing the Lawn 101 dB Motorcycle Riding 112 dB Concerts 125 dB Shooting Range 130 dB

Examples of Noisy Equipment Equipment Noise Level Back Hoe 85-95 decibels Chain Saw 110 decibels Front-end Loader 90-95 decibels Gunshot 140 decibels Jackhammer 112 decibels Lawn Mower 90 decibels Tractor 95-105 decibels Circular Saw 90-100 decibels “These noise levels are approximate.” 11

Recognizing Occupational Hazardous Noise Task Avg. Noise Level (dBA) Operating forklift 87 Cutting Wood 93 Cutting lawn 94 Installing trench conduit 95.8 Welding 98.4 Grinding 99.7 Chipping Concrete 102.9 Working near Generator 116 Tools Avg. Noise Level (dBA) Lathe 81 Welding Equipment 94.9 Hand Power Saw 97.2 Screw Gun, Drill 97.7 Rotohammer 97.8 Chop saw 98.4 Stationary Power tool 101.8 Chipping Gun 103.0

Non-Occupational Hazardous Noise Recognizing Noisy Hobbies Loud music Firearms Car/motorcycle race track Sporting events Loud speakers Household noises Crying babies Vacuum Lawn mower Power tools Ipod/Boom box

Noise Monitoring Used to identify work locations where hazardous noise levels exits. Employee exposures to noise monitored periodically with: Sound Level Meter (area noise level) Noise Dosimeter (personal noise exposure level)

Noise Map (Area Monitoring)

Noise Dose (Personal Monitoring)

Table of Permissible Noise Exposure Limits Sound Level (dBA) Permitted Duration per Workday (hours) 90 8.00 103 1.32 91 6.96 104 1.15 92 6.06 105 1.00 93 5.28 106 0.86 94 4.60 107 0.76 95 4.00 108 0.66 96 3.48 109 0.56 97 3.03 110 0.50 98 2.63 111 0.43 99 2.30 112 0.38 100 2.00 113 0.33 101 1.73 114 0.28 102 1.52 115 0.25

Impulsive or Impact Noise Exposure to impulsive or impact noise should not exceed 140 dB peak sound pressure level.

Daily Allowable Exposure Times to Noise The table below shows noise levels and how long a person can be exposed without hearing protection before there is damage to the ear. Noise Level Allowable Exposure Time 85 decibels 8 hours 90 decibels 4 hours 100 decibels 1 hour 105 decibels 30 minutes 110 decibels 15 minutes 115 decibels 0 minutes “These limits are found in the WISHA regulations on noise and are based on scientific studies of the effects of loud noise on people. You can work in areas with these noise levels as long as you have proper hearing protection – ear muffs or ear plugs.” 10

Affected Employees Employees subjected to noise exceeding permissible noise limits shall be provided hearing protection devices, if feasible administrative or engineering controls failed to reduce noise levels. Employee exposed to noise at or above the 8-hour time-weighted average (TWA) of 85 dB, or equivalently, a dose of 50% shall be notified and enrolled in HCP.

Noise Control Administrative Control Engineering Control Personal Protective Equipment ( hearing protective devices)

Administrative Controls Operate noisy equipment on second or third shifts. Rotate employees through high-noise areas. Modify existing machinery. Place noise limit specs. on new equip.

Administrative Controls (cont) Maintain equip. in good condition. Use noise control when installed. Reporting noisy equip. to supervisor for repair.

Engineering Controls Reduce noise at the source. Interrupt the noise path. Reduce reverberation & structural vibration.

Personal Protective Equipment (Hearing Protection Devices - HPD) Shall provide to employees exposed to 8 hr TWA of 85 dB at no cost. Employers shall ensure protection being worn: When exposed to 8 hr TWA of 90dB or greater by employees exposed to 8 hr TWA of 85dB or greater when: Whose baseline audiogram has not been established Who have experienced a threshold shift

Hearing Protection Device (HPD) (NRR) HPD must reduce employee noise exposure below PEL e.g. below 8 hr TWA of 90 dB. Employees with standard threshold shift (STS), HPD must reduce employees noise exposure below an 8 hr TWA of 85 dB. Noise Reduction Ratio (NRR) Convert dose to TWA; subtract 7 from NRR; subtract remainder from TWA to obtain the est.TWA under ear protector Subtract 7 from NRR; subtract remainder from TWA to obtain the est. TWA under ear protector

Noise Reduction Rating (NRR) Defined as the maximum number of decibels (dB) that the hearing protector will reduce the sound level when worn. NRR must be on the hearing protector package. NRR example for A-weighted data Estimated exposure (dBA) = TWA (dBA) - (NRR - 7)

Noise Reduction of Hearing Protection The “noise reduction rating” or “NRR” of hearing protection is measured in decibels. The NRR is found on the earmuff or earplug package. The higher the number, the greater the protection. “Since lab conditions are not the same as workplace conditions, the actual noise reduction is at least 7 decibels less the printed NRR. Many experts say actual protection is only half the NRR rating on the package.” 24

Hearing Protection Use Voluntary Use: Exposed to an 8 hr TWA of 85 dB Mandatory Use: Exposed to an 8 hr TWA of 90 dB Exposed to an 8 hr TWA of 85 dB but have not had a baseline hearing test Employees who have suffered STS hearing loss and are exposed to an 8 hr TWA of 85 dB

Employee Responsibility Understand the need for hearing protection devices. Wear HPDs and seek replacements. Encourage co-workers to wear HPDs. Communicate problems to supervisors.

Management Responsibility Provide occupational noise training. Provide hearing protection devices. Demonstrate commitment – wear HPDs. Enforce the use of HPDs. Keep up to date with HPD selection and use. Encourage questions and resolve problems.

Purpose of Hearing Protectors Reduction of sound waves traveling to the inner ear

Advantages and Disadvantages of Different Types of Hearing Protectors Kind of Protector Advantages Disadvantages Ear Plug Free head movements Good for tight work spaces Worn with any hairstyle Worn with hats, eye protection, respirators Good protection against high frequency sounds Can work loose during the work day Must be replaced periodically Small and can easily be lost Ear Muff Headband can be adjusted for comfort Seldom come loose during the work day Difficult to wear with eye, head and breathing protection

Attenuation of Different Types of Hearing Protectors Ear Plugs Reduce noise by as much as 30 decibels Ear Canals Used when individual is unable to use traditional ear plugs Ear Muffs Reduce noise by as much as 15-30 decibels Use in conjunction with ear plugs when exposed to high noise levels (105+ decibels)

Instructions on Selection, Fitting, Use, and Care of Hearing Protectors Ear plugs Keep clean and free of materials Wash in mild liquid detergent and warm water Squeeze excess water and air dry Discard plugs when hardened or do not re-expand Ear Canals Clean like normal ear plugs Do not tamper with the headband and the acoustic seal

Instructions on Selection, Fitting, Use, and Care of Hearing Protectors Ear Muffs Keep clean and free of debris Clean cushions with warm soapy water Do not tamper with the acoustic seal between the cushions and the headband Do not modify the ear muffs in any way Do not stretch or abuse the headband

Audiometric Testing Conducted by a qualified audiologist. Baseline Audiogram/Test Shows initial hearing status For comparison to future audiograms Periodic (Annual) Audiogram/Test To determine if HCP is effective and if non-noise factors affects hearing Recheck audiogram or professional referral necessary if significant hearing change occurs

Purpose of Audiometric Testing To measure hearing by sending tones to each ear through headphones. To show how one’s hearing compares to normal hearing based on age. Determine whether hearing is being conserved. Alert employee & employer for noise, age or medical related hearing loss.

Explanation of Test Procedures Audiometer sends tones to each ear through headphones. Listen & respond each time you hear a tone. Levels at which you can barely hear the tones is your hearing threshold levels. Audiogram records threshold (dB) for different pitches or frequencies (Hertz).

Evaluation of Audiogram Annual audiogram compared to baseline audiogram to determine threshold shift If threshold shift; Employee must be notified in writing within 21 days

Evaluation of Audiogram (cont) If threshold shift from occ. noise exp.; Employee fitted with hearing protectors, trained in use and care, required to use them. Employee refitted with better attenuation hearing protectors and retrained in hearing protector use Refer employee to eval/exam if add. testing necessary or if medical pathology is caused by hearing protectors Inform employee of need to eval/exam if medical pathology unrelated to hearing protectors is suspected

Evaluation of Audiogram (cont) If subsequent audiogram to noise exp. less than 8 hr TWA of 90dBA indicates that threshold shift is not persistent: Inform employee of new audiogram May discontinue required use of hearing protectors

Normal Hearing Mild Hearing Loss Moderate Hearing Loss Severe Hearing Loss Profound Hearing Loss

What is an Audiogram ? Severe hearing loss Normal hearing An audiogram is a printed chart of the results of the hearing test. They look similar to the results below. “The blue x’s are one ear, the green circles are the other ear. The hearing loss shown in these audiograms is in the higher frequencies which is commonly caused by exposure to excessive noise.” [examples of audiograms used at your company can be shown here. You can also discuss here how audiometric testing is provided at your company.] Severe hearing loss Normal hearing 36

Standard Threshold Shift Hearing ability changed by an average of 10 dB Employee notification within 21 days. Revised hearing protection required. Further medical evaluation. Allowance may be made for the contribution of aging.

Audiometric Test Requirements Test shall be pure tone, air conduction, hearing threshold exam. Test frequencies from 500 to 6000 Hz in each ear. Audiometers shall meet ANSI S3.6 and Appendix B Audiometric exams administered in room shall meet Appendix C

Audiometer Calibration Audiometer functional operation shall be checked daily. Audiometer calibration shall be checked acoustically annually per Appendix D

Training Provide annually to employees who are exposed to noise at or above 8 hr TWA of 85 dB. Topics must include: Effects of Noise on Hearing Purpose of Hearing Protectors Advantages and Disadvantages of Different Types of Hearing Protectors Attenuation of Different Types of Hearing Protectors Instructions on Selection, Fitting, Use, and Care of Hearing Protectors Purpose of Audiometric Testing

Record Keeping Employee Exposure Measurements Audiometric Tests Audiogram/Noise Exposure Assessment Job classification Audiometer calibration date Hearing Protection Devices Used Audiometric Test Rooms Background sound pressure level in test room

Proper Use of Hearing Protection It takes just a few minutes of unprotected exposure at noise above 115 decibels to risk hearing damage. Earplugs not well inserted into the ear canal will not provide complete protection. Likewise, earmuffs not snug against the head will “leak” noise into the ear. (glasses) “DOSH regulations require that we post a warning sign like this one at the entrance or perimeter of an area where the noise level is above 115 decibels.” 28

Summary Constant exposure to noise over 85 dB can cause hearing damage. Hearing loss can not be cured or repaired. Hearing tests are conducted annually. Hearing protection devices include ear plugs, ear muffs, and canal caps.

QUIZ Employee participation in the Hearing Conservation Program is required when exposed to an 8 hr TWA noise level of ____ decibels. Hearing damage can easily be repaired with surgery. True or False Describe a sign of hearing loss: _______ Name two off-work activities that may expose you to high-noise levels. Your company keeps records of noise monitoring and hearing tests. True or False

QUIZ A noise dosimeter is used to test an employee’s hearing capability. True or False Describe one of the ways noise impacts the workplace. ____________________________ Name two kinds of hearing protection devices: _______________ and __________________ In order to look for hearing loss, how often are hearing tests conducted? ________________ Name one of the ways management attempts to control employee noise exposure: _____________________________________

Types of Hearing Protection There are three types of hearing protection – ear muffs, earplugs and ear caps. Ear muffs and earplugs provide about equal protection, ear caps somewhat less. earmuffs “The WISHA noise regulations require that we have at least 2 types of hearing protection for you to choose from.” earplugs ear caps 14

What is an Audiogram ? Severe hearing loss Normal hearing An audiogram is a printed chart of the results of the hearing test. They look similar to the results below. “The blue x’s are one ear, the green circles are the other ear. The hearing loss shown in these audiograms is in the higher frequencies which is commonly caused by exposure to excessive noise.” [examples of audiograms used at your company can be shown here. You can also discuss here how audiometric testing is provided at your company.] Severe hearing loss Normal hearing 36

What happens when people are exposed to excessive noise? Question 1 What happens when people are exposed to excessive noise? a) They can’t hear someone talking to them. b) Over a period of time, they will develop hearing loss. c) Some people may develop permanent ringing in their ears. d) Some people will be stressed out by constant exposure to loud noise. “All these answers are correct. If the noise level is over 85 decibels, it can be difficult to carry on a conversation. Hearing loss is an inevitable result of long-term noise exposure. Ringing in the ears is also called ‘tinnitus’. Studies have shown that exposure to excessive noise can be stressful.”

Question 2 What is the lowest level of noise that can cause hearing loss? When it hurts your ears. 65 decibels c) 85 decibels d) An average of 85 decibels over 8 hours. d) Is the correct answer for most people. ( a small minority of people can have hearing loss at lower levels) If the noise hurts your ears, it is way over the level that will cause hearing loss. 65 decibels is the level of normal conservation. A two-hour exposure to 85 decibels will not hearing loss, but a two hour exposure to 95 decibels will likely cause hearing loss over the long run.

Question 3 What is NRR? The noise level of rifles. The noise rating of any loud machinery. The noise reduction rating of hearing protection. A measure of how well earplugs work. The correct answer is c). All hearing protection is rated by how many decibels they reduce noise to the ear. d) Is also correct as a general answer, but the NRR applies to earmuffs as well as ear plugs.

Question 4 Ear plugs work better than ear muffs in blocking out noise. a) True. b) False. c) It depends. The answer is false, they are equally effective. Ear muffs work slightly better at blocking out low-frequency noise.

Question 5 Why is audiometric testing required ? a) To make sure you haven’t gone deaf. b) To test for any hearing loss during your employment. c) To test the noise of machinery. d) To see how well you remember noise training material. “ b) is the correct answer. Mild hearing loss is often not noticed at first. Naturally, you don’t need a test to know if you have gone deaf.”

Anatomy of the Human Ear

Anatomy of the Human Ear

Sound Levels

OSHA Noise Standard 2 Program Strategy – TWA- Time Weighted Average Noise Exposure Program – 90 dBA 8 hour TWA(Equivalent Exposure Concept) Hearing Conservation Program – 85 dBA 8 hour TWA TWA- Time Weighted Average

Noise Control Measures Engineering Controls – Enclosure, Sound Dampening and Absorption Administrative Controls Use of Hearing Protection Devices - Noise Reduction Rating (NRR)

An Ear’s Anatomy Illustration: The Ear Foundation accessed from WWW.OSHA.gov 1. Eardrum 2. Malleus 3. Incus 4. Stapes 5. Semicircular canals 6. Cochlear Nerve 7. Vestibular nerve 8. Endolymphatic sac 9. Eustachian tube 92

Anatomy & Physiology of Normal Ear Semicircular Canals Stapes Auditory Nerve Ear Canal Cochlea Ossicles Ear Drum Eustachian Tube