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Occupational Noise Measurement

Occupational and Environmental Noise Risk Identification and Assessment to Validate Controls and Hearing Conservation ProgramPresented by: Bernard L Fontaine, Jr., CIH, CSP, Managing Partner, The Windsor Consulting Group, Inc. 2013 by The Windsor Consulting Group, Inc. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of The Windsor Consulting Group, Inc.

Occupational Noise Exposure Course Learning Objectives

Participants will be able to:Describe the consequences to health and well being of excessive noise exposureUnderstand the measurement (including dosimetry) of noise in relation to current standardsConduct surveys in the workplace to assess risks from noiseCopyright 2013 The Windsor Consulting Group, Inc.

Occupational Noise Exposure Course Learning Objectives

Awareness of noise hazards in the workplace, at sporting events, and during recreational activity Direct and indirect effect of noise on peopleIdentification and assessment of noise risk Understanding of hearing and hearing lossInterpret data based on exposure standardsSelect possible noise control measures including hearing protectionCopyright 2013 The Windsor Consulting Group, Inc.

Occupational Noise ExposureTopics to be Discussed

Physical properties of sound and human effectRisk assessment and noise surveysAnalysis and interpretation of noise dataNoise controls engineering and administrativeEducation and training requirementsAudiometry and hearing disordersEnvironmental noise sources and effectCopyright 2013 The Windsor Consulting Group, Inc.

4

Occupational Noise ExposureWHAT THIS COURSE WILL NOT PROVIDE:

The course is not intended to provide the skills to become an acoustics expertSelect the proper engineering controls based on octave band analysisSpecific instruction on how to operate noise measurement equipment or perform audiometryComprehensive discussion on hearing protectors or audiometric determination

Copyright 2013 The Windsor Consulting Group, Inc.

5

Occupational Noise ExposureWHAT THIS COURSE WILL NOT PROVIDE:

Exposure information on super low, extremely low, and tremendously low frequency used in submarine and mine transmission or man-made noise

Exposure information on high, very high , super high, extremely high, and tremendously high frequency noise from radio and television broadcast, microwave or wave scanners, satellite communications, radio astronomy, ultrafast molecular dynamics, condensed matter physics or amateur radio noise

Copyright 2013 The Windsor Consulting Group, Inc.

6

What is Noise?Noise is an unpleasant / unwanted soundTypes of noiseContinuousImpulseImpact

Side effects of noiseLoss of hearingPhysiological/psychological stressAccidentsBehavioural effectsNegative impact on health

Copyright 2013 The Windsor Consulting Group, Inc.

7Noise means different things to different people (e.g. rock music and elderly parents). Noise can get in the way of sounds we would rather hear. We are exposed to noise at work, home and in traffic. If it gets loud enough it can cause problems.

Hearing is one of life's important gifts (babies crying, etc.) How it effects us depends on age, health, frequency of sound, length of exposure.

(i) Continuous - music, grinders, engineers running(ii) Impulse - pneumatic tools, punch press, gun shots - more damaging.

Difference - length of time over which the sound occurs, both can create noise at damaging levels.

Side effect of noise:(i) Behavioural effects - annoyance and agitation(ii) Stress induced problems - high blood pressure and stomach ulcers(iii) Fatigue and impaired concentration causes an increase in errors(iv) Speech interference - poor communication and safety risks causing accidents(v) Reduction in productivity level - distracting(vi) Loss of hearing

Loud noises can cause hearing lossProlonged exposure to a harmless noise can cause hearing lossDamage from hearing loss is irreversibleNoise induced hearing loss is preventablePrevention involves:Noise controlsSafe work practicesEducation

Occupational Noise ExposureCopyright 2013 The Windsor Consulting Group, Inc.

8Experts have identified that prolonged exposure to too much noise causes deafness.

One of the important facts to grasp is that hearing loss resulting from industrial noise develops slowly and becomes progressively worse through continued exposure. This phenomenon prevents the exposed person from being aware of the danger until it is too late.

In most cases, loss of hearing takes place over a number of years. Gradual changes in hearing could be blamed on the persons age.

Once deafness occurs it cannot be rectified by surgery or medication.

This program will discuss methods of noise control (e.g. barriers and exposure reduction, safe work practices - PPE)

Occupational hearing loss is the most common work-related illness in the United States. Approximately 22 million U.S. workers exposed to hazardous noise levels at work, and an additional 9 million exposed to ototoxic chemicals. An estimated $242 million is spent annually on workers compensation for hearing loss disability.

Occupational Noise ExposureCopyright 2013 The Windsor Consulting Group, Inc.

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Sound Versus NoiseSound is a pressure change detectable by the human ear.Pitch (frequency) ranges between 20 to 20,000 HzVolume ranges between 0 to 140 dB (decibels)

Noise is a type of sound.Carries no informationRandomGenerally described as undesirable or unwanted sound

Copyright 2013 The Windsor Consulting Group, Inc.

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(Illustration: OSHA.gov)

Effects cardiovascular system

Effects the nervous system

Interferes with speech and concentration

Causes annoyance, stress, and fatigue

Reduces work efficiency

Lowers morale

Masks warning sounds

Non-Auditory Effects of NoiseCopyright 2013 The Windsor Consulting Group, Inc.

11

Illustration: Microsoft Clip Art

Non-Auditory Effects of NoisePsychological can startle, annoy, and disrupt concentration, sleep, or relaxation.

Interference with communication, resulting in interference with job performance and safety.

Physiological noise induced hearing loss, aural pain, or even nausea.

Copyright 2013 The Windsor Consulting Group, Inc.

12

Illustration: Microsoft Clip Art

The Physics of Sound

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The Physics of Sound

Copyright 2013 The Windsor Consulting Group, Inc.

The Physics of Sound

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

Copyright 2013 The Windsor Consulting Group, Inc.

Sound is a fluctuation in pressure above and below the ambient pressure of a medium that has elasticity and viscosity.

The medium may be a solid, liquid, or gas.

Sound is also defined as the auditory sensation evoked by these oscillations in pressure

Sound PropagationCopyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

Period (T) is the time it takes to complete one full cycle

Frequency (f) is the number of times per second a complete wave passes a point. The number of cycles per second is termed Hertz (Hz).

The period and the frequency are simply related by the following equation:

T = 1/f (seconds)Copyright 2013 The Windsor Consulting Group, Inc.

Properties of SoundSpeed (c) of sound in air is governed by air density and air pressure which in turn relates to the ambient temperature and elevation at or above sea level

At sea level, the speed of sound in air is about 343 m/s

Sound travels about 1 kilometres in 3 seconds (much slower than the speed of light)Copyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

Wavelength () is the length of one complete cycle, and is measured in meters (m).

It is related to the frequency (f) and speed of sound (c) by:

Wavelength () = c/f metersCopyright 2013 The Windsor Consulting Group, Inc.

Properties of SoundFrequencyWavelength100 Hz3 x 107 m1000 Hz3 x 106 m10,000 Hz3 x 104 m1 x 106 Hz/1 MHz300 m10 MHz3 m100 MHZ0.3 m1,000 MHz0.3 m

Wavelength in air at standard atmospheric conditionsCopyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of SoundSLMs have electronic circuits which convert the microphone signal to an RMS sound pressure level

The RMS pressure is used because it can be related to the average intensity of the sound or the loudness of the sound

For a pure (simple sine wave) tone it can be shown that the peak pressure and the RMS pressure are related:

Prsm = Ppeak = 0.707 x Ppeak 2For more complex signals, there is no simple relationship between the two

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

Peak sound is important to measure

In particular for loud impulsive or impact noise, such as gunfire, explosions or punch presses.

The Crest Factor is the ratio of the peak amplitude of a waveform to the RMS value.

Short intense impulses or impacts will have high CF values.

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of SoundSound power is defined as the total sound energy generated by the source per unit of time.

Sound power is expressed in units of watts (W) and sound intensity is vector quantity.

It is important to keep in mind that for all practical situations the sound power of a source output is constant regardless of its location (i.e. inside vs. outside).

Conversely, the sound intensity and sound pressure will change as a function of the environment in which it is located. Copyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

Sound pressure is expressed as force per unit area, and the unit is the Pascal (Pa).

Keep in mind sound pressure is the effect of a disturbance. The actual cause of the disturbance, and the resulting reaction effect, is due to sound power measured in decibelsdecibel = 20log (pa /po )

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of SoundSound Pressure Level:

The L in each expression stands for Level, and the I, W, and p terms represent intensity, power, and pressure, respectively for hearing at 1000 Hz.

Reference intensity (Iref) = 10-12 w/m2

Reference power (Wref) = 10-12 w

Reference pressure (pref) = 2 x 10-5 N/m2, or 20 Pa

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

A point sound source will radiate sound power evenly in all directions, assuming there are no reflective surfaces present. As the power spreads spherically from its origin, the surface area in increases and so the power per unit area decreases.

The total power remains the same, but the enclosing area is increasing, which results in a decrease in the sound intensity. This is known as the inverse-square law.

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of SoundSound intensity is based on surface area of sphere = 4 r 2

Therefore at 1 meter from source power will be spread over a sphere whose surface area is 4 x1

At 2 meters this will be 4 x 4 (i.e., 4 times as large and thus the Intensity will be one quarter).

At 3 meters the surface will be 32 = 9 times bigger, thus as the distance from source spreads the energy per unit area diminishes.Copyright 2013 The Windsor Consulting Group, Inc.

Properties of SoundIn air, the expression for each acoustical property is:

Sound Intensity Level:

Sound Power Level:

Copyright 2013 The Windsor Consulting Group, Inc.

Properties of Sound

The decibel scale and use of reference levels

Level is used as understood in the term water level i.e. height relative to something else, say the riverbank.

The softest sounds heard about 0.000,000,000,001 watts/m2

Saturn rocket at lift-off is greater than 100,000,000 watts/m2

Copyright 2013 The Windsor Consulting Group, Inc.

Common Sound Levels

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Common Sound Levels1 dB change barely perceptible to person with excellent hearing

3 dB difference would be just perceptible to the average listener

5 dB change clearly noticeable

10 dB increase typically perceived as twice as loud.

Copyright 2013 The Windsor Consulting Group, Inc.

Decibel AdditionAddition is a simple sum

Adding; 89.0dB plus 85.0dB plus 90.0dB

10log [ 1089/10 + 1085/10 + 1090/10] = 93.2 dBCopyright 2013 The Windsor Consulting Group, Inc.

Decibel AdditionNumerical differencebetween levelsLP1 and LP2 (dB)Amount to beadded to the higherof LP1 or LP2 (dB)*03.012.522.131.841.551.261.070.880.690.5100.4greater than100.0 for all practical purposes

Copyright 2013 The Windsor Consulting Group, Inc.

Decibel Subtraction

This can be done using the equation

Subtracting; 85 from 90dB.

10log [ 1090/10 - 1085/10] = 88.3dB

Alternatively the table for addition of dB can be used in an iterative mannerCopyright 2013 The Windsor Consulting Group, Inc.

Average Sound Level PressureThe equation to determine the average sound level for a number of measurements of a source is:

Averaging; 81, 86, 82 and 84dB.

10log 1/4[ 1081/10 + 1086/10 + 1082/10 + 1084/10] = 83.7dBCopyright 2013 The Windsor Consulting Group, Inc.

Directivity of Sound Propagation

Copyright 2013 The Windsor Consulting Group, Inc.

Frequency Characteristics of Sound

Workplace sounds are not simple sine waves

Broad spectrum of frequencies can to be divided into smaller bandwidths to assist the analysis for risk assessment, noise control, evaluation of hearing protection etc.

The sound level meter may contain a filter measure selected bandwidths of concern or a frequency analyser can be used. Most common bandwidths are

octave bandsthird octave bandsCopyright 2013 The Windsor Consulting Group, Inc.

Overall Sound Level by Frequency

Frequency, (Hz)63125250500100020004000SPL (dB re 20Pa)95728580868279Rearranging in ascending order 72798082858695Difference70.210.524.9Add0.832.52.52.11.2Cum. level dB79.88385.58890.196.2

Copyright 2013 The Windsor Consulting Group, Inc.

Octave Frequency Analysis

Copyright 2013 The Windsor Consulting Group, Inc.

Weighted Sound LevelsMicrophones and human ears have a different frequency response.

Several weighting networks (or frequency filters) were designed to make the SLM respond to frequency like our ear.

The accepted frequency for occupational and environmental noise is the A weighting.

Common weightings are A, C, Z and linearCopyright 2013 The Windsor Consulting Group, Inc.

Weighted Sound LevelsFrequency, HzA weightingC weightingZ weighting16-56.7-8.531.5-39.4-3.063-26.2-0.8125-16.1-0.2250- 8.6-0.0Flat500- 3.2-0.0from10Hz100000to 20kHz2000+ 1.2-0.24000+ 1.0-0.88000- 1.1-3.016000- 6.6-8.5

Copyright 2013 The Windsor Consulting Group, Inc.

Weighted Sound Levels

Copyright 2013 The Windsor Consulting Group, Inc.

Equal Loudness ContoursCopyright 2013 The Windsor Consulting Group, Inc.

Human Audible Range of Hearing

The normal range in human hearing is 20 Hz to 20,000 Hz. Sound at higher frequencies is called Ultrasound whereas lower frequencies is Infrasound

Human sensitivity to hearing based on configuration of the ear is greatest from 2,000 to 5,000 Hz

Minimum audible field in the most sensitive range is close to 0 dB, which is 20Pa This is the principal reason 20Pa is designated the international reference pressure for determining SPLCopyright 2013 The Windsor Consulting Group, Inc.

Time-Varying Noise SourcesCompressors, fans, electric motors etc. generally produce sounds that are continuous or steady-state.

A steady-state sound remains relatively constant in time, varying by less than +/- 3 dB

But what if they cycle off and on?

Sources with levels that fluctuate more than 3 dB are generally classified as variable noise sources like a brake press

Which part of the noise should we measure?

Copyright 2013 The Windsor Consulting Group, Inc.

Time-Varying Noise Sources

Copyright 2013 The Windsor Consulting Group, Inc.

Time-Varying Noise SourcesAnother type of time varying noise is that produced as an impact or impulse.

Impact sound can be generated by the solid collision between two objects, such as hammering, dropped objects, a door slamming shut, metal-to-metal impacts, etc. or by explosions such as gun fire or explosive tools.

Impulse sound is defined as an event having an exponential rise time constant of 35 milliseconds, and an asymmetric decay time constant of 1.5 seconds. Copyright 2013 The Windsor Consulting Group, Inc.

Anatomy of the Human Ear

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Anatomy of the Human Ear

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Healthy Cochlea

The cilia ( sensory hairs) appear normal

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Damaged Cochlea

Loss of cilia from noise exposure

Copyright 2013 The Windsor Consulting Group, Inc.

Threshold ShiftsTemporary Threshold Shifts (TTS) hearing returns to normal after noise exposure

Permanent Threshold Shifts (PTS) repeated noise exposure without a return to normal

Standard Threshold Shifts (STS) > 10 dB average loss in 2000, 3000, or 4000 Hz in either earCopyright 2013 The Windsor Consulting Group, Inc.

55

Noise and AcousticsHazardous noise exposures can occur

On the Job

Off the JobCopyright 2013 The Windsor Consulting Group, Inc.

56Noise damage can occur on-the-job as well as off-the-job (loud music, shooting, power tools, crowd noise). Good hearing conservation should be practiced, no matter what the setting.

Noise and AcousticsNoise-Induced Hearing LossCauses no painCauses no visible traumaLeaves no visible scarsIs unnoticeable in its earliest stagesAccumulates with each overexposureTakes years to notice a change

Is Permanent + 100% PreventableCopyright 2013 The Windsor Consulting Group, Inc.

57Noise damage is different from most other occupational injuries. It causes no pain or visible trauma (the ears do not bleed when hearing is being damaged), it leaves no visible scars, it is unnoticeable in its earliest stages (workers with noise-induced hearing loss often do not even notice themselves that they are losing hearing until it is too late), it accumulates with each over-exposure, and it generally takes years to diagnose. ( to add bottom line message) But Noise-Induced Hearing Loss (NIHL) is permanent and 100% preventable.

Noise and AcousticsNoise Intensity or Sound PressureFrequency or PitchLength of Daily ExposureDuration of Exposure in YearsIndividual SusceptibilityOther Factors (disease, genetics, lifestyle, medication, age, etc.)Factors Affecting Hearing LossCopyright 2013 The Windsor Consulting Group, Inc.

58Noise damage is different from most other occupational injuries. It causes no pain or visible trauma (the ears do not bleed when hearing is being damaged), it leaves no visible scars, it is unnoticeable in its earliest stages (workers with noise-induced hearing loss often do not even notice themselves that they are losing hearing until it is too late), it accumulates with each over-exposure, and it generally takes years to diagnose. ( to add bottom line message) But Noise-Induced Hearing Loss (NIHL) is permanent and 100% preventable.

Noise and AcousticsWorkers CompensationIn many countries, excessive noise is the biggest compensable occupational hazard.

Cost of NIHL to developed countries ranges from 0.2 to 2% of its GDP. NIHL is on the rise globally. (Source: WHO)Copyright 2013 The Windsor Consulting Group, Inc.

59In many countries, excessive noise is the biggest compensable occupational hazard. Cost of NIHL to developed countries ranges from 0.2 to 2% of its GDP. NIHL is on the rise globally. (Source: WHO)

Noise and AcousticsUnited States StatisticsMost common occupational injury in the United States. 22 million US workers are exposed to hazardous noise at work on a daily basis. Approx. 8 million Americans suffer from NIHL. (Source: NIOSH, 2009)Copyright 2013 The Windsor Consulting Group, Inc.

60Most common occupational injury in the United States. 30 million US workers are exposed to hazardous noise at work on a daily basis. Approx. 10 million Americans suffer from NIHL. (Source: NIOSH)

Noise and Acoustics

Copyright 2013 The Windsor Consulting Group, Inc.

61Typical noise levels on-the-job and off-the-job a lawnmower at 94 dB, heavy equipment at 100 dB a rock concert at 120 dB. Unprotected exposures at these levels can cause damage. According to OSHA regulations, no exposures of any duration are allowed over 115 dB.

Noise Risk Register

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Risk Assessment

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Risk Register by Job Title

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Risk Register by Job Title

Copyright 2013 The Windsor Consulting Group, Inc.

Rank OrderNoise Risks

Noise Risk Register by Job Title

Chipping Concrete Floor 96 dBA (TWA) at 4.5 hours Copyright 2013 The Windsor Consulting Group, Inc.

Noise Risk Register by Job Title Sandblasting - 125 dBA (4 hour sample) Inside hood - 109 dBA

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Risk Register by Job Title 36" Wall Saw - 100 dBA (4.5 hour sample)

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Risk Management What is a safe level?

There is no simple answer as to what constitutes a safe noise exposure limit.

The answer involves the intricate and diverse variables associated with an persons susceptibility to noise and characteristics and magnitude of the noise exposure.

Hearing conservation measures include:

Noise exposure criteria of 85 dBA for the 8-hour workday ANDPeak levels should never exceed 140 dBC.

Copyright 2013 The Windsor Consulting Group, Inc.

OSHA Noise StandardProgram Strategy Noise and Hearing Conservation

Noise Exposure Program 90 dBA 8 hour TWA (Equivalent Exposure Concept)Hearing Conservation Program 85 dBA 8 hour TWATWA- Time Weighted AverageCopyright 2013 The Windsor Consulting Group, Inc.

Table G-16 - Permissible Noise ExposuresDuration per day, hoursSound level dBA slow response89069249539721001 1021105110 or less115

Footnote(1) When the daily noise exposure is composed of two or more periods of noise exposure of different levels, their combined effect should be considered, rather than the individual effect of each. If the sum of the following fractions: C(1)/T(1) + C(2)/T(2) C(n)/T(n) exceeds unity, then, the mixed exposure should be considered to exceed the limit value. Cn indicates the total time of exposure at a specified noise level, and Tn indicates the total time of exposure permitted at that level. Exposure to impulsive or impact noise should not exceed 140 dB peak sound pressure level.Copyright 2013 The Windsor Consulting Group, Inc.

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Noise Action LevelAction Level (AL) = 85 dBA for a 8-hour TWA

Determined without regard to hearing protector attenuation

Hearing Conservation Program (HCP) required when noise exposures equal or exceed the action level

Monitoring program implemented when noise exposures equal or exceed the action level

Copyright 2013 The Windsor Consulting Group, Inc.

72

Measurement of Noise Loudness170 dB Jet airliner130 dBPneumatic chipping and riveting120 dBRiveting hammer110 dBShouting loudly or automatic punch press 90 dB Construction site pneumatic drilling 70 dBStreet sounds 38 dBQuiet bedroom

This is a logarithmic scale an increase of 1dB meansabout 30% more noise

Copyright 2013 The Windsor Consulting Group, Inc.

Exposure Level vs. Duration

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Measuring Equipment Sound Level Meters (SLM) Continuous on-mobile sources

Noise Dosimeters Mobile various sources

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Measuring Equipment

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Measuring Equipment

There are two types or classes of SLMs established by International Standards

Class 1 - precision meter, and Class 2 - general purpose instrument with lower performance specifications than Class1

Measurements are undertaken with the appropriate class of SLMCopyright 2013 The Windsor Consulting Group, Inc.

Noise Measuring Equipment

There are three types of microphones

Random incidence microphones, (omni-directional) Direct incidence microphones, (free-field)Pressure microphones (pressure-response)

Most commonly used is the random incidence or omni-directional microphone

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Measuring Equipment

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Measuring Equipment

Copyright 2013 The Windsor Consulting Group, Inc.

SLM and Octave Band Analyzer

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Noise Measuring Equipment

Frequency analysis 1/3 octave-band spectral data for the sound levels generated by an internal combustion engine.

Copyright 2013 The Windsor Consulting Group, Inc.

Noise Measuring Equipment

A noise dosimeter is an SLM designed to measure a workers noise exposure over a period of time.

The output is available as both noise dose and noise exposure.

Noise exposure may be shown as an Leq,8h, LEX,8H, or TWA.

TWA - Time weighted average - implies an eight- hour (8-hour) average.Copyright 2013 The Windsor Consulting Group, Inc.

1/3 Octave Band Analyzer

Copyright 2013 The Windsor Consulting Group, Inc.

Case Study: Noise MonitoringCase Study: Consider a worker who undertakes these work tasks:

Use planer with noise level at the ear of 102 dBA for 0.5 hours

Use saw with noise level at the ear of 98 dBA for 4 hours

Use of drill with noise level at the ear of 89 dBA for 2.5 hours

Hammering with noise level at the ear of 92 dBA for 2 hours Copyright 2013 The Windsor Consulting Group, Inc.

85Engineering ControlsSound barriers should be placed between the noise source and employees.

Administrative ControlsLimiting the amount of time a worker spends in a high noise area or relocating work areas away from noise.

Hearing ProtectionPersonal hearing protection devices come in many forms and they decrease the exposure to noise.

One of the above must be in place in an area of 85 dBA.

OSHA Maximum Exposure TimeLeqTimeLeqTimeLeqTimeLeqTime8032.0908.01002.01100.508127.9917.01011.71110.448224.3926.11021.51120.388321.1935.31031.31130.338418.4944.61041.11140.298516.0954.01051.01150.258613.9963.51060.871160.228712.1973.01070.761170.198810.6982.61080.661180.16899.2992.31090.571190.14

Copyright 2013 The Windsor Consulting Group, Inc.

86Engineering ControlsSound barriers should be placed between the noise source and employees.

Administrative ControlsLimiting the amount of time a worker spends in a high noise area or relocating work areas away from noise.

Hearing ProtectionPersonal hearing protection devices come in many forms and they decrease the exposure to noise.

One of the above must be in place in an area of 85 dBA.

Noise Exposure MonitoringCalculate dose using the formula:

Dose = 100 x (C1/T1 + C2/T2 + C3/T3 + ... + Cn/Tn) where: Cn is the time spent doing each work taskand allowable

Tn = Calculated noise dose of planer at 102 dB for 0.5 hours, sawing at 98 dBA for 4 hours; drilling at 89 dBA for 2.5 hours; and hammering 92 dBA for 2 hours = 247.1% or 96.5 dBA for 8-hour TWA.82(L-90)/5

Copyright 2013 The Windsor Consulting Group, Inc.

87Engineering ControlsSound barriers should be placed between the noise source and employees.

Administrative ControlsLimiting the amount of time a worker spends in a high noise area or relocating work areas away from noise.

Hearing ProtectionPersonal hearing protection devices come in many forms and they decrease the exposure to noise.

One of the above must be in place in an area of 85 dBA.

Noise Exposure MonitoringSourceSPL,dBATime Hrs.OSHA maxPEL 8- Hrs.OSHA max PEL 9-HrsPlanar1020.51.5 ----Saw9842.6----Drill892.59.2----Hammer9226.1----Total9.0Over maximum 8-hoursLAeq,8h97 dBA3.0 Hrs. (180 mins.)2.7 hrs. (160 mins)

Copyright 2013 The Windsor Consulting Group, Inc.

88Engineering ControlsSound barriers should be placed between the noise source and employees.

Administrative ControlsLimiting the amount of time a worker spends in a high noise area or relocating work areas away from noise.

Hearing ProtectionPersonal hearing protection devices come in many forms and they decrease the exposure to noise.

One of the above must be in place in an area of 85 dBA.

Noise Risk AssessmentNo.Work Process or OperationLAeqTPeakRisk AssessmentComplies with OSHARequirements1Honda Bike67-Very LowYES2Cushman Truck75103LowYES3Cushman Sprayer76102LowYES4Quad Runner72101LowYES5Mower Reelmaster 83102LowYES6Mower Ransomes 83102LowYES7Mower John Deere 86105ModerateNO, if exposure exceeds 6 hrs. 36min.8Mower John Deere 90115HighNO, if exposure exceeds 2 hrs. 32min.9Blower Echo94108Very HighNO, if exposure exceeds 1 hr. 4 min.10Whipper Snipper Kawasaki98113Extremely HighNO, if exposure exceeds 25 min.

Copyright 2013 The Windsor Consulting Group, Inc.

89Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Noise Risk Assessment

Copyright 2013 The Windsor Consulting Group, Inc.

90Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

ANGLE GRINDERENGINEERING SHOPAPPALACHIAN FRUIT RESEARCH STA.Running (no load) 101.4 dBARunning (with load) 106.2 dBABENCH GRINDERENGINEERING SHOPAPPALACHIAN FRUIT RESEARCH STA.Running (no load) 76.3 dBARunning (with load) 92.1 dBA

Noise Risk Assessment Copyright 2013 The Windsor Consulting Group, Inc.

91

SCREW CHILLERQUARANTINE GREENHOUSEFOREIGN DISEASE / WEED SCI. RES. UNIT102.4 dBAWELL PUMPSWATER TREATMENT BUILDING APPALACHIAN FRUIT RESEARCH STA.82.8 dBANoise Risk Assessment Copyright 2013 The Windsor Consulting Group, Inc.

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RADIAL ARM SAWENGINEERING SHOPAPPALACHIAN FARMING SYSTEMS RESEARCH CENTERRunning (no load) 81.5 dBARunning (with load) 90.5 dBADRILL PRESSENGINEERING SHOPAPPALACHIAN FARMING SYSTEMS RESEARCH CENTERRunning (no load) 88.7 dBARunning (with load) 93.8 dBANoise Risk Assessment Copyright 2013 The Windsor Consulting Group, Inc.

93

GRINDING HOODSAPPALACHIAN FARMING SYSTEMS RESEARCH CENTER89.3 dBAAIR HANDLERQUARANTINE GREENHOUSEFOREIGN DISEASE / WEED SCI. RES. UNIT87.8 dBA

Noise Risk Assessment Copyright 2013 The Windsor Consulting Group, Inc.

94

FRUIT GRADER / SORTERFARM CENTER COMPLEX APPALACHIAN FRUIT RESEARCH STA.91.1 dBANoise Risk Assessment Copyright 2013 The Windsor Consulting Group, Inc.

95

Statistical Risk Modelling

Copyright 2013 The Windsor Consulting Group, Inc.

96Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Personnel Notification of ResultsThe employer shall notify each employee exposed at or above 85 dBA of the noise monitoring results.

Copyright 2013 The Windsor Consulting Group, Inc.

97

Photo: OSHA

Day-Night Environmental Test

WHO guideline for night noise (Lnight, outside) is 40 dB (2002.

Copyright 2013 The Windsor Consulting Group, Inc.

98Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Environmental Exposure ModelComparison of Day/Evening/Night ExposuresGuidance for Average Background Noise Levels, LA90,TType of AreaTime of DayDay (700-1800)Evening (1800-2200)Night (2200-700)Rural (i.e., negligible transportation)403530Semi rural and low density transportation454035Near some commerce or industry504540Near dense transportation555045Borders of industrial areas605550Within industrial areas656055

WHO interim guideline for night noise (Lnight, outside) is 55 dB (2002).Copyright 2013 The Windsor Consulting Group, Inc.

99Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Environmental Exposure Model

Copyright 2013 The Windsor Consulting Group, Inc.

100Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Inversion of Temperature and Sound

DaytimeNight and temperature inversionCopyright 2013 The Windsor Consulting Group, Inc.

101Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Wind Direction and Sound

Copyright 2013 The Windsor Consulting Group, Inc.

102Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Noise Engineering ControlsEnclosuresSound barriersComplete enclosureSound proof cabsMufflersEquipment and exhaust

Copyright 2013 The Windsor Consulting Group, Inc.

103Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Sound Contour MappingPlanograms

Copyright 2013 The Windsor Consulting Group, Inc.

104Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Sound Contour MappingPlanogramsCopyright 2013 The Windsor Consulting Group, Inc.

105Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Exposure Modelling Risk

Copyright 2013 The Windsor Consulting Group, Inc.

106Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Exposure Modelling Risk

Copyright 2013 The Windsor Consulting Group, Inc.

107Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Exposure Modelling Risk

Copyright 2013 The Windsor Consulting Group, Inc.

108Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Exposure Modelling Risk

Copyright 2013 The Windsor Consulting Group, Inc.

109Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Exposure Modelling Risk

Copyright 2013 The Windsor Consulting Group, Inc.

110Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Noise and Acoustics

Hierarchy of Controls

ADMINISTRATIVE CONTROLSRotate WorkersExtended Breaks2nd/3rd Shift

ENGINEERING CONTROLSBuy QuietVibration PadsEnclosuresBarriersIsolation

PERSONAL PROTECTIVE EQUIPMENT

Copyright 2013 The Windsor Consulting Group, Inc.

111For hazardous noise exposures, the hierarchy of controls should be 1) Engineering Controls 2) Administrative Controls 3) Hearing Protection

Noise Engineering Controls

NOISE

TransmittedTransmitted

FlankingIncidentReflectedCopyright 2013 The Windsor Consulting Group, Inc.

Absorbed

112Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Noise Engineering Controls

Copyright 2013 The Windsor Consulting Group, Inc.

113Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Sound Transmission Loss

Multiple layer panels combine a sound absorption material with a high transmission loss material to form a composite system.

Can be sound absorbing material on one side or a complex sandwich panel with a number of layersCopyright 2013 The Windsor Consulting Group, Inc.

114Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Sound Transmission Loss

Copyright 2013 The Windsor Consulting Group, Inc.

115Enclosures - an operative enclosure can cut down by 20 dBA.

Barriers - best if close to person or machine and depends on the frequency of the noise. 10 dBA reduction in noise.

Complete enclosure gives good noise reduction 20-40 dBA.

Proper maintenance of equipment and exhausts prevents the extra noise of unoiled machines and dirty exhausts.

Administrative ControlsIf engineering controls are not feasible, administrative controls should be considered:

Rotate employees to reduce exposureLimit number of at-risk workersModify or upgrade existing machinerySpecify noise limit on new equipmentMaintain and repair equipment/machinery Post signs for workers to use hearing protection Report noisy equipment/machinery to supervisor

Copyright 2013 The Windsor Consulting Group, Inc.

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. Types of Hearing Protection

EarmuffsEarplugsEar capsCopyright 2013 The Windsor Consulting Group, Inc.

117

Hearing ProtectionSelection and UseEnsure it is suitable for the jobMake sure it hearing device does not interfere with other safety equipmentDiscard disposal ear plugsRegular maintain ear muffs and ear channel capsHome-made protectors dont work (e.g., cotton, wool)Use hearing protection with communication devices

Copyright 2013 The Windsor Consulting Group, Inc.

Noise and AcousticsOverprotection/Underprotection

20-25% workers exposed between 80-90 dB will still get NIHL. While HPD use is mandatory at 90 dB, you should protect to at least 85 dB.

Avoid overprotection protected levels below 65-70 dB can create additional safety risk.Copyright 2013 The Windsor Consulting Group, Inc.

11920-25% workers exposed between 80-90 dB will still get NIHL. While HPD use is mandatory at 90 dB, you should protect to at least 85 dB.Avoid overprotection protected levels below 65-70 dB can create additional safety risk.

Sports and Recreational ActivitiesProtect your hearing off the job too

Loud musicPersonal stereosCar entertainmentElectronic devicesLawn mowersChain sawsFire arms and fireworksSporting eventsRacing Highway driving with vehicle windows open

Copyright 2013 The Windsor Consulting Group, Inc.

Hearing Protector AttenuationFor overexposed employees and those at-risk of being over exposed

At a minimum attenuate < 90 dBA 8-hr TWA

For workers with an STS attenuate < 85 dBA 8-hr TWA

Whenever noise exposures increase risk to more workers exposed, change in operation, process or machinery

Reevaluated to determine adequacy of the selected devices

Copyright 2013 The Windsor Consulting Group, Inc.

121Photo: Oregon OSHA

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 dataEstimated exposure (dBA) = TWA (dBA) - (NRR - 7) Example (plugs or muffs): TWA = 109 dBA, NRR= 29 109 - (29-7) = 109 dBA - 22dB = 87 dBA

Copyright 2013 The Windsor Consulting Group, Inc.

Current NRR Label Mock-up of New Label

80th %Minimally-trained

20th %Proficient Users

Noise Reduction RatingCopyright 2013 The Windsor Consulting Group, Inc.

123The EPA has announced its intention to modify the EPA label, changing the single number rating to a two-number range. The low point on that range would represent the 80th percentile (the level that most minimally-trained users could achieve), and the high point of that range would represent the 20th percentile of protected workers (the level the some proficient users could achieve).

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.Proper Use of Hearing Protection

Copyright 2013 The Windsor Consulting Group, Inc.

124

Audiometric Testing ProgramBaseline audiometric test taken when noise exposures equal or exceed the action level. A qualified person performs the hearing test, usually an audiologist.Results interpreted by qualified personAudiometer checked before each use and calibrated acoustically annually Records of calibrations required

Copyright 2013 The Windsor Consulting Group, Inc.

125

Audiometric TestingProvided at no cost to the employee

Baseline audiogram within 6 months of first noise exposure at or above action level

For mobile test van, < 12 months

Provided initially and annually

Allowance for aging

STS notification

Copyright 2013 The Windsor Consulting Group, Inc.

126Illustration: Microsoft Clip Art

Example of Audiogram

BaselineAnnualCopyright 2013 The Windsor Consulting Group, Inc.

Chart: NCDOL-OSH Division

STS NotificationRecall standard threshold shift (STS) definition:

> 10 dB avg. loss 2kHz 4 kHz

Employer may retest within 30 days to verify the STS.

Audiologist shall determine need for further evaluation.

Employer shall notify the affected employee of the STS in writing within 21 days.Copyright 2013 The Windsor Consulting Group, Inc.

128

Audiogram with Hearing Loss

2KHz3KHz4KHzCopyright 2013 The Windsor Consulting Group, Inc.

Chart: NCDOL-OSH Division

Personnel Training

Training is required for employees who are exposed to noise at or above 8 hr. TWA of 85 dB.Topics must include:Effects of noise on hearingPurpose of hearing protectorsAdvantages and disadvantages of hearing protectorsAttenuation of hearing protectorsInstructions on selection, fitting, use, and care of hearing protectorsPurpose of audiometric testing

Copyright 2013 The Windsor Consulting Group, Inc.

130

MS Clip Art

Post the StandardMake available to affected employees or their representatives copies of the standard.

Post a copy of the standard in the workplace

Copyright 2013 The Windsor Consulting Group, Inc.

131

RecordkeepingPermanent hearing loss is a OSHA recordable illness

Provide access to employee exposure monitoring and audiometric data

If business terminates. transfer records to successor or forward documents to NIOSH

Otherwise, keep noise measurements: > 2 years

Audiometric tests > employment duration:

Name, job classification and dBA-TWADate, examiners name and calibration dateBackground measurements of audiometric test room

Copyright 2013 The Windsor Consulting Group, Inc.

132

Dont Take Noise for Granted!

Hearing damage creeps up on youHearing loss is easily preventableOnce it has happened, there may be no cureCopyright 2013 The Windsor Consulting Group, Inc.

Contact: Bernard L Fontaine, Jr., CIH, CSP The Windsor Consulting Group, Inc.Email: [email protected]: 1+ 732.221.5687

140

120

100

80

Decibel

60

- Noise Control Program

40

- Hearing Conservation

20

0 2 4 6 8

Exposure Duration (Hours)