1. OSHA Occupational Noise 29 CFR 1910.95
Clark Safety
&
Loss Control

2. 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

3. Definition of Noise
“Unwanted Sound”

4. 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 ?

5. 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

6. When is Noise Too Loud ?

7. When is Noise Too Loud ?

8. 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

9. 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 or ] 7

10. 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

11. 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.

12. 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.

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

14. 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

16. 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.

17. Anatomy of the Human Ear

18. Anatomy of the Human Ear

19. 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.

20. 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.

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

22. 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.

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

24. 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

25. Anatomy & Physiology of Healthy Ear

26. Anatomy & Physiology of Damaged Ear

27. 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.

28. Anatomy & Physiology of Damaged Ear

29. 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.

30. 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

31. 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

32. 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

33. 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.

34. Effects of Age & Noise on Hearing

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

36. Examples of Noisy Equipment
Equipment Noise Level
Back Hoe decibels
Chain Saw decibels
Front-end Loader decibels
Gunshot decibels
Jackhammer decibels
Lawn Mower 90 decibels
Tractor decibels
Circular Saw decibels
“These noise levels are approximate.” 11

37. 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

38. 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

39. 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)

40. Noise Map (Area Monitoring)

41. Noise Dose (Personal Monitoring)

42. 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

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

44. 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

45. 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.

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

47. 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.

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

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

50. 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

51. 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

52. 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)

53. 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

54. 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

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

56. 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.

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

58. 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

59. 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 decibels
Use in conjunction with ear plugs when exposed to high noise levels (105+ decibels)

60. 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

61. 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

62. 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

63. 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.

64. 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).

65. 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

66. 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

67. 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

68. Normal Hearing
Mild Hearing Loss
Moderate Hearing Loss
Severe Hearing Loss
Profound Hearing Loss

69. 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

70. 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.

71. 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

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

73. 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

74. 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

75. 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

76. 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.

77. 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

78. 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: _____________________________________

80. 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

81. 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

82. 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.”

83. 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.

84. 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.

85. 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.

86. 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.”

87. Anatomy of the Human Ear

88. Anatomy of the Human Ear

89. Sound Levels

90. 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

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

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

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