Reducing the Risk of Noise-Induced Hearing Loss Through Best Practices Theresa Y. Schulz, PhD, LtCol, USAF (ret.)

Reducing Costs for Hearing Loss
Topics Noise And Acoustics Noise Reduction Reducing Costs for Hearing Loss Motivating Workers NOTE: WHEN YOU PLAY THIS SLIDE IN SLIDESHOW, EACH LISTING ON THE LEFT WILL HAVE A CORRESPONDING EXPLANATION ON THE RIGHT There are many factors that are important for the selection of the right hearing protector. COMFORT – Comfort is one of the most important because if an HPD is uncomfortable, people won’t wear it. And we all know how much noise reduction you get from a hearing protector you aren’t using: 0 dB !!! In a NIOSH study, workers cited communication as the number 1 reason for not using HPDs. The right hearing protector should feel comfortable. One protector may not satisfy all workers. Offer a variety of earplugs or earmuffs to meet varying. worker needs and preferences. NOISE REDUCTION – Selecting HPDs with suitable attenuation for noise environment. Avoid overprotection in marginal noise environments. Consider banded earplugs for intermittent noise or electronic earmuffs for impact noise. SIZE – Every ear canal has its own shape and size. Ensure proper fit with variety of earplug sizes and shapes. Sized multiple-use earplugs. Low-pressure foam earplugs for smaller ear canals. COMMUNICATION – Keep workers connected to their environment. Uniform attenuation allows speech/signals to be hear more naturally. Sound amplification earmuffs for workers with hearing impairment. The issues with communication can be solved by having the right about of noise reduction, using flat attenuation earplugs or earmuffs such as Clarity, or with communication earmuffs or Impact earmuffs depending on the environment. JOB REQUIREMENTS – Consider job requirements in HPD selection. Detectable earplugs for process industries. Hi-visibility earmuffs for dark/high traffic areas. dielectric HPDs for electrical environments. HYGIENE – Proper care and maintenance can extend life and performance of HPDs. Examine and clean all multiple-use earplugs daily. Clean and replace ear cushions on earmuffs every 4-6 months USE WITH OTHER PPE – Avoid compromising overall safety when wearing other PPE. Cap-mounted earmuffs for hard hats. Multiple-position earmuffs for full-brim hard hats. Ultraslim neckband earmuffs with welding shields.

Noise + Acoustics

Noise + Acoustics Non-Occupational Occupational
Typical 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 + Acoustics Noise-induced hearing loss is the most common permanent and preventable occupational injury in the world. The extent of the problem is shown in this statistic: The World Health Organization reported a few years ago that noise-induced hearing loss is the most common permanent and preventable occupational injury in the world. World Health Organization

Worker’s Compensation
Noise + Acoustics Worker’s Compensation In 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) In 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)

United States Statistics
Noise + Acoustics United States Statistics Most 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) Most 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 ~ Hierarchy of Controls
Noise + Acoustics - Hierarchy of Controls NOISE AND ACOUSTICS ~ Hierarchy of Controls ENGINEERING CONTROLS Buy Quiet Vibration Pads Enclosures Barriers Isolation ADMINISTRATIVE CONTROLS Rotate Workers Extended Breaks 2nd/3rd Shift PERSONAL PROTECTIVE EQUIPMENT For hazardous noise exposures, the hierarchy of controls should be … 1) Engineering Controls 2) Administrative Controls 3) Hearing Protection

OSHA Update: Feasibility
Noise + Acoustics - OSHA Update OSHA Update: Feasibility Oct 2010 – Intent to change interpretation of “feasibility” Must use engineering controls that are capable of being done First extended comment period then withdrew that interpretation Proposing public hearings and asking NIOSH and professionals for input

NOISE AND ACOUSTICS ~ Hierarchy of Controls
Noise + Acoustics Ototoxic Chemical Exposures Confirmed Ototoxics Ethyl Benzene Lead and inorganic compounds (as Pb) Styrene Toluene Trichloroethylene Possible Carbon disulfide n-Hexane Xylene Ototoxic by themselves Synergistic effect with noise Large differences in sensitivity Recommend: increased frequency of audiometric testing Synergistic Ototoxics Carbon Monoxide Hydrogen Cyanide NOISE For hazardous noise exposures, the hierarchy of controls should be … 1) Engineering Controls 2) Administrative Controls 3) Hearing Protection

Noise Reduction Rating (NRR)

Noise Reduction Rating
Noise Level = 100 dB Noise Reduction Rating = dB How much noise is reaching the ear of the worker ? Confusion about the proper application of a hearing protector’s rated attenuation has led to many to assume that most workers obtain protection at a level that equals noise minus NRR. But the amount of noise reaching the eardrum of a particular worker is completely unknown. That is completely unknown … (55 – 104 dB)

A laboratory estimate of the amount of attenuation achievable by 98% of users when properly fit A population-based rating ― some users will get more attenuation, some will get less The Noise Reduction Rating is a laboratory estimate of the amount of attenuation achievable by 98% of users when properly fit. It is a population-based rating … some users will get more attenuation, some will get less. The NRR is only a population estimate, not a predictor of individual attenuation.

Noise Reduction Rating – Determining an NRR
10 human subjects tested in a simulated industrial room Tested with ears open / occluded at nine frequencies Each subject tested 3x NRR calculated to be population average Hearing protectors are tested in a laboratory sound room which is intended to simulate a typical noisy setting in industry. Subjects are tested with ears open (no hearing protectors) and occluded (with hearing protectors), and the difference between those measurements is the noise reduction of the HPD. The attenuation measurements for all subjects are then input into a formula (the measurements are logarithmically added, two standard deviations are subtracted to account for variability, and 3 dB is subtracted to account for the different noise spectrums in industry). The result is the Noise Reduction Rating (NRR). A test subject in the Howard Leight Acoustical Lab, San Diego, CA, accredited by the National Voluntary Laboratory Accreditation Program (NVLAP)

NRR Noise Reduction Rating – Determining an NRR NRR
5 4 Number of test subjects 3 2 30 Subject test results (10 x 3) 1 14 18 20 22 24 26 28 30 32 19 23 25 27 Attenuation

De-Rating Methods OSHA NRR ÷ 2 (feasibility of engineering controls) NIOSH Earmuffs NRR – 25% Formable Earplugs NRR – 50% All Other Earplugs NRR – 70% CSA Class A up to 100 B up to 95 C up to 90 Fit Test The mistrust of NRRs has led to the promulgation of several de-rating schemes. But once again, none of these does anything to predict the individual protection to be expected from a particular user.

Noise Reduction Rating –
Real-World Attenuation ≠ NRR Real user attenuation <0 to 38 dB 192 users of a flanged reusable earplug ~ 27 NRR 50 NRR = 27 Multiple-Use Earplug 40 30 Retraining and refitting resulted in an average 14 dB improvement for this group Attenuation in dB 20 There is quite a bit of variability in the attenuation obtained by users in the real world. This may be due to intentional factors (not inserting the HPD far enough in order to make it less intrusive, or more comfortable) or unintentional factors (improper sizing of HPD, poor seal around earmuffs, etc.). This scattergram shows the results of one study, indicating a wide variety of real-world attenuations for 192 workers wearing an earplug with a laboratory NRR of 27 dB. (<Space> to show retraining benefit.) Researchers in this study then took the workers with the lowest attenuation, and refit/retrained them in using the HPD properly. This resulted in an average 14 dB improvement in measured attenuation. The moral of the story? The effectiveness of an HPD relies heavily upon proper training and fitting by the wearer. 10 -10 From Kevin Michael, PhD and Cindy Bloyer “Hearing Protector Attenuation Measurement on the End-User”

Biggest Factors in Achieving NRR 1.FIT 2. WEAR TIME 30 dB A worker who selects an earplug with an NRR of 30 5 min 10 min 15 min 30 min but then removes that HPD for just … Regardless of which HPD is selected, there are two factors that determine whether an employee in the real-world will achieve the laboratory NRR: Fit, and Wear Time. This slide addresses wear time (fit will be discussed a bit later). This slide shows examples of a user who removes his HPD for just 5 minutes (cumulative) in an 8-hour workday. In noise exposures, small intervals of no protection quickly void large intervals of adequate protection. [<space> to show the effect of removing HPD for 10/15/30 minutes per workday] If a worker selects an earplugwith 30 dB of rated protection, but then removes that earplug for just 30 minutes cumulative in his 8-hour workday, it is as though he is only wearing a protector rated with an NRR of 18 dB. effectively reduced his 8-hour NRR to just … 26 dB 24 dB 22 dB 18 dB In noise exposures, small intervals of no protection quickly void large intervals of adequate protection.

The EPA recently made an announcement about a proposed change to the Noise Reduction Rating [NRR] This is the first change in hearing protector regulation in nearly 30 years At the beginning of August 2009, the EPA recently made an announcement about a proposed change to the Noise Reduction Rating [NRR]. This is the first change in hearing protector regulation in nearly 30 years

80th % Minimally-trained 20th % Proficient Users The 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). Current NRR Label Mock-up of New Label

Rating methods are based upon idealized laboratory testing NRR has been criticized for being too generous in its prediction of noise reduction [attenuation] Studies indicate that while some workers in real-world worksites achieve the NRR on the package or even greater protection, many workers do not This has led to a variety of inappropriate de-rating methods for hearing protectors Contributed too much confusion in knowing how to accurately estimate a HPD’s attenuation As background, attenuation rating methods are based upon idealized laboratory testing. NRR has been criticized for being too generous in its prediction of noise reduction [attenuation]. Studies indicate that while some workers in real-world worksites achieve the NRR on the package or even greater protection, many workers do not. This has led to a variety of inappropriate de-rating methods for hearing protectors. Contributed too much confusion in knowing how to accurately estimate a HPD’s attenuation.

The New System: A Range Represents a range of expected protection Uses a new ANSI-standard lab testing to generate the attenuation ratings New NRR will provide an indication of how much attenuation minimally-trained users [the lower number] versus highly-motivated trained users [the higher number] can be expected to achieve For some hearing protectors, the spread of this range may be quite significant The EPA has proposed changing the Noise Reduction Rating [NRR] from a fixed number to a range of attenuation. Represents a range of expected protection. This new NRR uses a new ANSI-standard lab testing to generate the attenuation ratings. The new NRR will provide an indication of how much attenuation minimally-trained users [the lower number] versus highly-motivated trained users [the higher number] can be expected to achieve. For some hearing protectors, the spread of this range may be quite significant.

Current vs. Proposed NRR Current NRR Proposed NRR Rating A single-number estimate of protection A high/low range of estimated protection Description of Rating Estimates the 98th percentile of protection obtained by users when properly fitted Estimates the 80th and 20th percentile of protection obtained by users Test Protocol ANSI S [Experimenter Fit] 10 subjects for earplugs and earmuffs, HPDs fit by experimenter ANSI S Method A [Supervised Subject-Fit] 20 subjects [for earplugs] or 10 subjects [for earmuffs], HPDs fit by subject after brief training This slide demonstrates the differences between the current and proposed NRR.

Current vs. Proposed NRR Current NRR Proposed NRR Application Intended for use with dBC noise measurements Requires a 7 dB correction for use with dBA noise measurements. Can be applied directly to dBA noise measurements De-Rating Various de-rating schemes promulgated by various organizations [including OSHA] Designed to be used with no required de-rating Retesting Currently, no retesting of HPDs required Periodic retesting of HPDs required every 5 years

NRR Labels The proposed EPA regulation addresses for the first time the rating of non-standard hearing protectors, such as Active Noise Reduction [ANR] or level-dependent [or impact noise] protectors Under the old labeling requirements, these specialized protectors were rated with a low NRR, simply because they were not tested in the higher noise ranges where their noise reduction capability is activated EPA has included these types of hearing protectors in its new labeling regulation so that purchasers can make informed choices The proposed EPA regulation addresses for the first time the rating of non-standard hearing protectors, such as Active Noise Reduction [ANR] – such as noise cancellation headsets used during travel - or level-dependent [or impact noise] protectors – such as Impact Sport-styled earmuffs. Under the old labeling requirements, these specialized protectors were rated with a low NRR, simply because they were not tested in the higher noise ranges where their noise reduction capability is activated. EPA has included these types of hearing protectors in its new labeling regulation so that purchasers can make informed choices.

Three New Labels LABEL DESCRIPTION Conventional HPD Perform lab test with subjects who fit the protector after brief training Estimates the range of protection achieved by 20% and 80% of users Active Noise Reduction [ANR] Uses a Microphone-in-Real-Ear [MIRE] method to estimate protection Measured with ANR turned OFF and ON to show the additional attenuation from the ANR Level Dependent/ Impulse Noise Reduction Testing will occur over a range of impulse noise levels. Multiple tests to determine lower and upper ranges of impulse noise reduction Will include two ranges to identify attenuation for passive and active modes This slide covers the three new proposed labels, and the different types of HPDs will be tested.

Determining New NRR 20 human subjects tested in a simulated industrial room Subject trained then fits their own earplugs Tested with ears open / occluded at 9 frequencies Each subject tested 2x NRR calculated to be population average Hearing protectors are tested in a laboratory sound room which is intended to simulate a typical noisy setting in industry. Subjects are tested with ears open (no hearing protectors) and occluded (with hearing protectors), and the difference between those measurements is the noise reduction of the HPD. The attenuation measurements for all subjects are then input into a formula (the measurements are logarithmically added, two standard deviations are subtracted to account for variability, and 3 dB is subtracted to account for the different noise spectrums in industry). The result is the Noise Reduction Rating (NRR).

New NRR (NRsa) 80% achieved > 20 dB 20% achieved > 26 dB
5 4 Number of test subjects 3 2 40 Subject test results (20 x 2) 1 11 14 18 20 22 24 26 28 30 33 19 23 25 27 Attenuation

How to Apply the New Label Two-number range displays the estimated protection achievable by minimally-trained users [80%] versus proficient users [20%]. A wider range indicates greater variability in the fit of that HPD. Smaller ranges indicate more consistency of fit. For example, earmuffs will usually have a tighter fitting range than earplugs, and may have a smaller NRR range. 80% 20% The new label will display a range of attenuation for each HPD. Two-number range displays the estimated protection achievable by minimally-trained users [80%] versus proficient users [20%]. A wider range indicates greater variability in the fit of that HPD. Smaller ranges indicate more consistency of fit. For example, earmuffs will usually have a tighter fitting range than earplugs, and may have a smaller NRR range.

Why did the EPA decide to make this change? Since 1974, the EPA has used the Noise Reduction Rating as its yardstick to measure hearing protector effectiveness in reducing noise levels NRR is based upon idealized laboratory testing, many studies indicate the NRR can over-estimate the protection received by many workers The new Noise Reduction Rating will take into better consideration the human factors involved with the use of HPDs – specifically training and fit Since 1974, the EPA has used the Noise Reduction Rating as its yardstick to measure hearing protector effectiveness in reducing noise levels. NRR is based upon idealized laboratory testing, many studies indicate the NRR can over-estimate the protection received by many workers. The new Noise Reduction Rating will take into better consideration the human factors involved with the use of HPDs – specifically training and fit.

Why is a two-number range part of the new label? It is a more realistic indicator of the variety of protection levels achieved by users in the real world, depending on their training and fit In the past, some safety managers assumed that the attenuation rating on the package would be achieved by most workers, regardless of training or motivation Two-number range now clearly shows that employees who use the same HPD can obtain different levels of protection Employees who are motivated and trained to achieve a proper fit will be nearer the high end of the range A two-number range on the label is a more realistic indicator of the variety of protection levels achieved by users in the real world, depending on their training and fit. In the past, some safety managers assumed that the attenuation rating on the package would be achieved by most workers, regardless of training or motivation. Two-number range now clearly shows that employees who use the same hearing protector can obtain different levels of protection. Those employees who are motivated and trained to achieve a proper fit will be nearer the high end of the range.

Will OSHA 29 CFR change? OSHA has not announced any proposed changes to the Occupational Noise Standard OSHA will presumably respond to the revised NRR label by issuing a field directive or technical memorandum, informing its compliance officers how to deal with the new two-number NRR range OSHA has not announced any proposed changes to the Occupational Noise Standard. OSHA will presumably respond to the revised NRR label by issuing a field directive or technical memorandum, informing its compliance officers how to deal with the new two-number NRR range.

Will the new rating methods favor earplugs or earmuffs? While a well-fit foam earplug generally has greater attenuation than most earmuffs, earmuffs are inherently easier to fit for most users There is less variability in the fit of earmuffs Overall range of attenuation for earmuffs will usually be tighter and often higher, than earplugs Workers should be offered a choice of earplugs, bands and earmuffs that meet the requirements of the work environment While a well-fit foam earplug generally has greater attenuation than most earmuffs, earmuffs are inherently easier to fit for most users. There is less variability in the fit of earmuffs. Overall range of attenuation for earmuffs will usually be tighter and often higher, than earplugs. Workers should be offered a choice of earplugs, bands and earmuffs that meet the requirements of the work environment.

EPA’s Published Timetable Action Date CFR Cite NPRM 08/05/09 74 FR 39150 NPRM Comment Period Extended 08/21/09 74 FR 42223 Period End 09/04/09 Period Extended To 11/04/09 Final Action 09/00/10

What Can I Do Now? Although the new labeling regulation takes effect whenever the final rule is published by the EPA, there are a number of actions you can take now to prepare your Hearing Conservation Program for the change. Evaluate Noise Spectra to determine if spectral balance corrections will be necessary Upgrade to One-on-one Training research studies confirm that one-on-one training is superior to group training Although the new labeling regulation takes effect whenever the final rule is published by the EPA, there are a number of actions you can take now to prepare your Hearing Conservation Program for the change. 1. Re-evaluate Current HPD Selection – to determine whether they are appropriate for your noise environment. Use the Howard Leight Hearing Protector Selector – - for recommendations. 2. Provide Better Training – on proper fit of hearing protectors. Hold a “Toolbox Training” and hold a refresher fit training session.

What Can I Do Now? Evaluate Current HPD Selection to determine whether they are appropriate for your noise environment. Use the Howard Leight Hearing Protector Selector for recommendations. Update Hearing Conservation Training Program on proper fit of hearing protectors. Hold a “Toolbox Training” and hold a refresher fit training session. Although the new labeling regulation takes effect whenever the final rule is published by the EPA, there are a number of actions you can take now to prepare your Hearing Conservation Program for the change. 1. Re-evaluate Current HPD Selection – to determine whether they are appropriate for your noise environment. Use the Howard Leight Hearing Protector Selector – - for recommendations. 2. Provide Better Training – on proper fit of hearing protectors. Hold a “Toolbox Training” and hold a refresher fit training session.

What Can I Do Now? Use VeriPRO® fit testing Train how to properly fit HPDs Select appropriate HPDs Document adequate protection Use QuietDose™ In-ear dosimetry measures and documents the noise dose employee is exposed to during their work shift Use VeriPRO fit testing to train how to properly fit HPDs, select appropriate HPDs and document adequate protection. Use QuietDose in-ear dosimetery to document the noise dose employee is exposed to during their work shift.

Reducing Costs of Hearing Loss

Workers Compensation Claims Data
Reducing Costs of Hearing Loss Workers Compensation Claims Data Source: Texas Department of Insurance

Fit Testing In-Ear Dosimetry
Reducing Costs of Hearing Loss Fit Testing In-Ear Dosimetry There are now two methods that allow users to measure the fit and exposure protection in the workplace” Fit Testing (using a system like VeriPRO) In-ear Dosimetry (using a system like QuietDose)

NHCA Basics Workshop: Effective Hearing Protection February 24, 2011 Field Verification – Fit-Testing Earplug Fit Testing Provides an accurate, real-world picture of your employees’ hearing protector effectiveness. ID if your employees are: Getting the right protection Need additional training Need different earplug As a problem solver: Derating Schemes One-on-One Training HPD Selection NRR Change Use VeriPRO fit testing to train how to properly fit HPDs, select appropriate HPDs and document adequate protection. Use QuietDose in-ear dosimetery to document the noise dose employee is exposed to during their work shift. Theresa Y. Schulz, PhD 42

Attenuation at Threshold
NHCA Basics Workshop: Effective Hearing Protection Field Verification – Fit-Testing February 24, 2011 Real-Ear Attenuation at Threshold (R.E.A.T.) At the 2006 NHCA conference, we hosted a workshop to review the four common methods of measuring attenuation of an earplug in the field. These methods are as follows: - Real Ear Attenuation at Thresholds (REAT), as used in FitCheck by Dr. Kevin Michael - Real-Ear Attenuation Above Threshold (REA-AT), as used in VeriPRO - F-MIRE, as used by Sonomax / AEARO - In-Ear Dosimetry, as used in DoseBuster by Dr. Kevin Michael Theresa Y. Schulz, PhD 43

(Real-Ear Attenuation Above Threshold)
NHCA Basics Workshop: Effective Hearing Protection Field Verification – Fit-Testing February 24, 2011 Loudness Balance (Real-Ear Attenuation Above Threshold) At the 2006 NHCA conference, we hosted a workshop to review the four common methods of measuring attenuation of an earplug in the field. These methods are as follows: - Real Ear Attenuation at Thresholds (REAT), as used in FitCheck by Dr. Kevin Michael - Real-Ear Attenuation Above Threshold (REA-AT), as used in VeriPRO - F-MIRE, as used by Sonomax / AEARO - In-Ear Dosimetry, as used in DoseBuster by Dr. Kevin Michael Theresa Y. Schulz, PhD 44

Microphone in Real-Ear
NHCA Basics Workshop: Effective Hearing Protection Field Verification – Fit-Testing February 24, 2011 Microphone in Real-Ear (M.I.R.E.) At the 2006 NHCA conference, we hosted a workshop to review the four common methods of measuring attenuation of an earplug in the field. These methods are as follows: - Real Ear Attenuation at Thresholds (REAT), as used in FitCheck by Dr. Kevin Michael - Real-Ear Attenuation Above Threshold (REA-AT), as used in VeriPRO - F-MIRE, as used by Sonomax / AEARO - In-Ear Dosimetry, as used in DoseBuster by Dr. Kevin Michael Theresa Y. Schulz, PhD 45

Microphone in Real-Ear
NHCA Basics Workshop: Effective Hearing Protection Field Verification – Fit-Testing February 24, 2011 In-Ear Dosimetry Microphone in Real-Ear (M.I.R.E.) At the 2006 NHCA conference, we hosted a workshop to review the four common methods of measuring attenuation of an earplug in the field. These methods are as follows: - Real Ear Attenuation at Thresholds (REAT), as used in FitCheck by Dr. Kevin Michael - Real-Ear Attenuation Above Threshold (REA-AT), as used in VeriPRO - F-MIRE, as used by Sonomax / AEARO - In-Ear Dosimetry, as used in DoseBuster by Dr. Kevin Michael Theresa Y. Schulz, PhD 46

Field Verification – Fit-Testing
Audiometric, IntregaFit,* 1,2 MultiFit FitCheck* HPDWellFit QuickFit 1 EARfit* SafetyMeter* VeriPRO* REAT, 1One freq REAT, 1One freq MIRE Loudness Balance Sound booth Quiet Room Anywhere PAR Derived PAR Any earplug Modified or custom earplugs COHC 2Training included Training provided Training included * Commercially available

OSHA Alliance: Best Practice Bulletin Additional Information What does OSHA feel about fit testing systems for hearing protection? In an OSHA Alliance Best Practices Bulletin (see link), seven benefits of fit-testing systems are offered, and the concept is endorsed as a best practice for Hearing Conservation Programs.

Published NRR Taken from a study of 101 workers at eight different companies, this scattergram shows how far away each worker was from the published NRR of the respective earplug they were using. About 1/3 of the workers had measured attenuation that were higher than the published NRR. About 1/3 were within the range about 5 dB below the published NRR. And about 1/3 of the workers had attenuation that was more than 5 dB below the published NRR. The bottom left photo shows the variety of earplugs that were tested in this study. This scattergram shows the danger in using de-rating policies like the oft-misapplied 50% de-rating by OSHA. If we were to summarily just assume that all earplugs only achieve 50% of the published NRR in the field, then clearly 2/3 of the workers are seriously overprotected, since they are achieving much higher protection than 50%.

Personal Factors Program Factors Reducing Costs of Hearing Loss Gender
Age Years in Noise Ear Canal Size Familiarity Model of Earplug Program Factors # Group Trainings # Personal Trainings What is the best predictor of a worker achieving good attenuation from an earplug? We looked at the following personal and program factors, and concluded there was only one strong factor that correlated with good protection: that factor was individual training. Workers who receive individual training in how to use their hearing protectors are more likely to achieve a high personal attenuation. All other factors just followed a random distribution.

REDUCING COSTS / CLAIMS
Reducing Costs of Hearing Loss REDUCING COSTS / CLAIMS Published NRR A second important factor in achieving good attenuation in the field is the option of trying a second hearing protector. If a worker obtains low attenuation with one type of earplug, will he obtain low attenuation with all types of earplugs? Our study showed the answer is definitely NO. Workers who tried a second pair of earplugs often had major leaps in attenuation, bringing them closer to the published attenuation. Trying a second earplug often improves attenuation

“How well can users predict their attenuation after a short fit-testing training session?" If workers get feedback about the effectiveness of their earplugs are they better able to predict the effectiveness of the next (and future) fits of earplugs? In this study, we fit-test construction workers several times within a few minutes and showed them the numerical result. Then they were tested once more without seeing the result and asked several questions.

Ability to Predict Noise Reduction
Fitting Tips Reducing Costs of Hearing Loss Ability to Predict Noise Reduction The real question was how closely they could estimate the attenuation provided by a given earplug after this short training session. And most were spot on! In all but 4 of the 34 ears (88%), workers were able to tell about how much attenuation the earplug provided. The important point is that workers could tell a good fit from a poor fit, even if they were off by 5-8 dB. This is a vast improvement over workers having really no clue about how much attenuation (or protection) their earplugs provide.

Reducing Costs of Hearing Loss Field Verification – Fit-Testing
"Learned A LOT about best earplugs for me" "I know how to better fit my earplugs now." "Recently had threshold shift" "Found better earplugs" "I had no idea I was not using my earplugs correctly." "Very glad I did the fitting test. Now I know the correct way to fit my ear plugs.” "I found a more comfortable fit. It was very beneficial." "I was amazed with the results after being shown the proper way to use earplugs. "Feel like am protected now!"

In-ear dosimetry measures/records worker’s actual noise dose, with and without protection
Provides real-time monitoring and alerts when worker approaches/exceeds safe limits Only metric with direct potential to measure and prevent further progression of occupational hearing loss In-ear dosimetry records and monitors a worker’s actual noise dose, both with or without hearing protection.

The typical sequence of measurements from in-ear dosimetry on an individual worker may look something like this. Initially, measured noise doses are quite high (over 100%). As the worker receives feedback about the overexposures, the daily noise doses work their way downward, until nearly all noise doses are below 50%.

Research > Alcoa Intalco Works
Reducing Costs of Hearing Loss Research > Alcoa Intalco Works Mean Hearing Threshold (2k, 3k, 4kHz): – 2007 (N = 46) Employees using continuous in-ear dosimetry starting in 2005 Case Study: ALCOA Intalco (presented by Dr. Kevin Michael et.al. at AIHA 2007, used with permission)

Preventive Action after NIHL
Reducing Costs of Hearing Loss Preventive Action after NIHL In practice, an OSHA-recordable STS is not a preventive action …. It is documentation of a hearing loss after the fact. How soon will an employee suffering NIHL be re-fit / re-trained ? “Best case scenario” per Hearing Conservation Amendment In-ear dosimetry “worst case” scenario … 1 Day • Audiometric test • Retest • Notification By itself, OSHA’s Standard Threshold Shift is not a preventive measure. It documents hearing loss after the fact, and simply resets the clock for retesting without verifying whether preventive measures were successful. The annual audiogram is a “lagging indicator” of whether a Hearing Conservation Program is successful. In-ear dosimetry, however, gives users immediate feebback, allowing them to immediately adjust their protection level until they reach sufficient levels. In-ear dosimetry thus becomes a “leading indicator.” Months

Training + Motivation

Personalize Hearing Loss
Training + Motivation Personalize Hearing Loss Show, Don’t Tell Provide copy of annual audiogram to worker Use personal examples to demonstrate consequences of hearing loss Ask questions: What is your favorite sound? What sound would you miss the most if you couldn’t hear? What sounds connect you to people and your environment? We can motivate employees to wear their hearing protection if we can prove to them that they are not invincible nor invulnerable to noise-induced hearing loss. This can be accomplished by giving workers a copy of their audiometric test, or by clearly showing workers the noise hazardous noise levels at their worksite. Getting workers to think about what their hearing means to them can help to personalize their motivation to prevent noise-induced hearing loss.

Demonstrate Future Risk
Training + Motivation Demonstrate Future Risk Training Materials TXA&M It is human nature to weigh our risks in terms of “here and now.” But with noise-induced hearing loss, we must show the worker the future risk. This can be accomplished by means of audio demonstrations, or simulated hearing losses, so that the worker has a clear understanding of his future risk, and the need for adequate protection today. The links listed on this slide offer great training and educational resources, including audio demonstrations, that can be used in your HC training program.

Training + Motivation It is human nature to weigh our risks in terms of “here and now.” But with noise-induced hearing loss, we must show the worker the future risk. This can be accomplished by means of audio demonstrations, or simulated hearing losses, so that the worker has a clear understanding of his future risk, and the need for adequate protection today. The links listed on this slide offer great training and educational resources, including audio demonstrations, that can be used in your HC training program.

Send Clear Message On + Off Job
Training + Motivation Send Clear Message On + Off Job HC Part of Everyday Life Include recreational hearing conservation in annual training Provide extra HPDs for home use Promote Hearing Conservation at company/family events Many employers encourage their workers to use the company-provided hearing protectors off-the-job. After all, any noise-induced hearing loss (whether on- or off-the-job) will cause hearing loss which will be detected in the company-sponsored audiometric testing program. Proper use of hearing protectors both on and off the job will prevent noise-induced hearing loss. Emphasize that Hearing Conservation should be a part of everyday life, at both work and home. Include recreational HC training in your annual training. Many employers encourage their workers to use the company-provided hearing protectors off-the-job. After all, any noise-induced hearing loss (whether on- or off-the-job) will cause hearing loss which will be detected in the company-sponsored audiometric testing program. Proper use of hearing protectors both on and off the job will prevent noise-induced hearing loss.

Remove Barriers to HPD Use
Training + Motivation Remove Barriers to HPD Use Make HPDs Available Highlight “where to find HPDs” in annual training Make sure HPDs are well-stocked and accessible Include group of workers in selection process for increased acceptance Offer wide variety to match comfort, job requirements Compliance in wearing hearing protection will be greatest when we remove the barriers or excuses that employees may raise as objections. Is an adequate supply of hearing protectors available? Is there a reasonable selection of comfortable protectors for workers? Does the amount of attenuation match the noise level? Make HPDs Available Highlight “where to find HPDs” in annual training Make sure HPDs are well-stocked and accessible Include group of workers in selection process for increased acceptance Offer wide variety to match comfort, job requirements

Make Hearing Conservation Part of Your Everyday Life

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Reducing the Risk of Noise-Induced Hearing Loss Through Best Practices Theresa Y. Schulz, PhD, LtCol, USAF (ret.)

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Reducing the Risk of Noise-Induced Hearing Loss Through Best Practices Theresa Y. Schulz, PhD, LtCol, USAF (ret.)

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Presentation on theme: "Reducing the Risk of Noise-Induced Hearing Loss Through Best Practices Theresa Y. Schulz, PhD, LtCol, USAF (ret.)"— Presentation transcript:

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