How much do you love your hearing and why you should.

February 14, 2017

How much do you love your hearing and why you should.

Of all the five senses it seem that hearing is the most ignored and the most taken for granted. Our generation (Boomers, X&Y) have not done a very good job at preventing hearing loss until its too late.

Whether your 17 or 55 years old, we have all done some sort of damage to our hearing…. 

Some of us have worked in loud noisy places and haven’t really considered protecting our ears except with the odd foam earplug, which are only good for one shift. Or we have worked in an environment where the noise was gradual but still loud and did nothing to protect our hearing since it wasn’t top of mind.

Or how about everyday uses to protect your hearing from noise pollution. Over the past 10 years we all have been embracing iTunes, iPods, Podcasts, SmartPhones, Audiobooks etc. But have we really considered the extra strain all of these technological advances have impacted our ears? Well if you LOVE YOUR HEARING, then I suggest you start.  Remember we live with our hearing and we should love our hearing as it one of the 5 senses that allows to hear the wonderful things in life; things to consider next time you crank up that new hit song, or put in disposable instead of personal hearing protection.

Love your hearing

From all of us at ProtectEar USA – HAPPY VALENTINES DAY!


Basic Facts About Hearing Loss

  • About 20 percent of Americans, 48 million, report some degree of hearing loss.
  • At age 65, one out of three people has a hearing loss.
  • 60 percent of the people with hearing loss are either in the work force or in educational settings.
  • While people in the workplace with the mildest hearing losses show little or no drop in income compared to their normal hearing peers, as the hearing loss increases, so does the reduction in compensation.
  • About 2-3 of every 1,000 children in the United States are born with a detectable hearing loss in one or both ears.
  • Almost 15% of school-age children (ages 6-19) have some degree of hearing loss.

SOURCE: http://www.hearingloss.org/content/basic-facts-about-hearing-loss

The Quantification and Reporting of Hearing Protection Attenuation

February 8, 2017

ProtectEar has produced a series of three articles regarding the challenges to knowing how much protection is given to an associate in a hearing loss prevention program. This the 2nd article in the series, deals with the quantification and reporting of attenuation. The initial article dealt with the history of trying to measure and report attenuation. The final article deals with “After Hearing Loss Prevention, then what?” What are the next steps a firm can apply to go beyond the current practice in hearing loss prevention?

The Quantification and Reporting of Hearing Protection Attenuation

What is the NRR?

The U.S. Environmental Protection Agency (EPA) was charged by the Noise Control Act of 1972 with developing and enforcing regulations pertaining to Product Noise Labeling. As a result the EPA developed 40 CFR 211 Subpart B – Hearing Protective Devices, in which the Noise Reduction Rating (NRR) was defined. The NRR is a single-number rating which has been required by law to be shown on the label of each hearing protective device (HPD) sold in the United States since 1979.

NRR

Before any HPD may be sold in the United States, the manufacturer or distributor must have it tested according to the requirements of the law, submit the data to the EPA, and provide the NRR along with corollary information on the HPD’s packaging. The NRR was intended to allow the consumer to select an HPD appropriate for the noises in which it would be used to prevent noise-induced hearing loss (NIHL). The law requires that the values of sound attenuation used for calculation of the NRR be determined in accordance with ANSI S3.19-1974. It matters not whether the HPD is intended for protection from occupational or recreational noise, or even to reduce the impact of traffic noise or the snoring of a partner on sleep, it must be labeled with the NRR label and corollary information.

Real-ear attenuation at threshold (REAT) is determined by carefully measuring the hearing thresholds of ten (10) normal-hearing members of a subject panel. Their hearing thresholds are measured for narrow bands of noise in a highly specified acoustic environment. Each subject is tested twice; ears open and ears occluded with the HPD being tested. The experimenter-fit method defined in ANSI S3.19 is used. Rather than allowing the subject to put on or remove the HPD, the experimenter fits the hearing protector to the ear of each test subject for each occluded test for what they consider is a best fit. REAT is the difference between the thresholds with the ears occluded and the ears open. Each subject repeats the paired open/occluded test three (3) times. Mean attenuations and standard deviations are calculated in accordance with the standard.

NoiseHealth_

The NRR calculation is specified by the EPA’s law, not the ANSI S3.19 standard. The NRR is computed from the mean attenuations and standard deviations of the attenuations for each of the nine (9) narrow bands of noise. The NRR is intended to predict the minimum amount of protection provided to 98% of potential users.

How has the NRR been used?

The Hearing Conservation Amendment to the Occupational Noise Standard (OSHA, 1983) describes six methods for using the NRR to determine a worker’s protected A-weighted noise exposure. These methods vary according to the instrumentation and parameters used to determine the unprotected noise levels. However, they can be summarized into two basic formulas, depending on whether unprotected exposure levels were measured on a C-weighted or an A-weighted scale. For C-weighted measurements:

Protected dBA = unprotected dBC – NRR

where the protected dBA and the unprotected dBC are 8-hour time-weighted average1s (TWA1s) determined according to the Occupational Noise Standard.

This method is how the NRR was designed to be used. For example, if a protector has an NRR of 17 dB and it is used for an TWA[i] of 95 dBC, the noise level entering the ear could be expected to be 78 dBA [95 – 17 = 78] or lower in 98% of the cases if the protector is worn according to manufacturer’s specification as fitted by the experimenter during the testing.

For A-weighted measurements:

protected dBA = unprotected dBA – [ NRR – 7]

Where, again, the protected and unprotected dBA are 8-hour time-weighted averages determined according to the Occupational Noise Standard (1093).

This method is an adaptation for those whose instrumentation does not have C-weighting capabilities. The 7-dB correction factor is used to account for the de-emphasis of low-frequency energy inherent to the A-weighting scale.

So, for example, if a protector has an NRR of 17 dB and it is used for an environmental noise exposure level of 95 dBA, the noise level entering the ear could be expected to be 85 dBA [95 – (17 – 7) = 85] or less in 98% of the cases.

Problems with the NRR

A study by Berger, Franks, and LIndgren, (1996) evaluated data from 22 studies of real-world REATs. They found that labeled NRRs for the HPDs studied over-estimated the reported REATs by as little as 5% and by as much as 2000%.

NIOSH reevaluated the data and consequently recommended derating the NRR by a multiplicative factor of 75% for earmuffs, 50% for slow-recovery formable earplugs, and 30% for all other earplugs (NIOSH, 1998). The NIOSH derating scheme did not affect the 7-decibel dBC-to-dBA correction as it was applied to the NRR only. Derating was not applied to custom-molded earplugs, however, so they may range from extremely effective (meeting labeled NRR) to completely ineffective (providing no protection at all). It all depends upon the quality of the impression and the quality assurance of the laboratory making the earplug.

OSHA’s approach to using the NRR, while recognizing the NIOSH derating scheme, is to derate the NRR by 50% regardless of hearing protector type when considering whether an HPD will provide adequate hearing protection for a given noise exposure level expressed as a TWA.

Thus, if the noise exposure level were made in dBA, most often the case, the protected exposure level for a 95-dBA exposure and an HPD with an NRR of 29 dB would be 84 dBA – [95 – ((29-7)/2)], 1 dB less than the OSHA Action Level (OSHA, 2016).

So, what do I do with the NRR?

The best approach is to recognize the NRR for what it is: a number derived from a laboratory test that for most pre-molded earplugs and formable (foam) earplugs represents a fitting that you and your employees will not achieve. OSHA’s approach as defined by CPL 02-02-03 dated December 16, 1983 is as follows:

  • Use the NRR as the laboratory-based noise reduction for a given hearing protector.
  • Apply a safety factor of 50 percent; i.e., divide the calculated laboratory-based attenuation by 2.
    • NOTE: This is a general method for taking into consideration OSHA experience and the published scientific literature, which indicate that laboratory-obtained attenuation data for hearing protectors are seldom achieved in the workplace.
    • If a different or no safety factor seems appropriate in a particular instance, it may be used instead. For example, for laboratory-made custom-molded earplugs, NIOSH recommended that no safety factor (derating) be applied.
  • The adjusted noise reduction should be sufficient to meet requirement that the protected noise exposure level be less than the OSHA Action Level of TWA < 85 dBA.

So, if you are using custom molded earplugs, you can take the NRR on the label at face value and apply it as suggested above without applying a safety factor or derating it. For the custom molded earplug, it seems to not matter whether the experimenter or the subject fits it for testing. The outcome is about the same[ii]. 

What is the NRR(SF)?

A New Rating: A new “subject fit” or naïve subject method of measuring HPD attenuation can be used to calculate a different rating; the NRR(SF). The people (subjects) in this laboratory test fit their own protector according to the manufacturer’s instructions without the help of the person conducting the test. While the subjects are very well trained in taking hearing tests, they do not use HPDs regularly, have not participated in an experimenter-fit procedure, and have only used a few HPDs without formal training (hence naïve subject). Compared to the NRR shown on the current EPA label, the NRR(SF) is usually a lower rating that may be closer to the performance of the hearing protector in the real world.

The NRR (SF) was developed by the National Hearing Conservation Association’s (NHCA) Task Force on Hearing Protector Effectiveness to address labeling related issues (Royster, 1995).

How do I use the NRR (SF)?

The NRR(SF) is intended to be used directly with A-weighted noise exposure levels. Thus, the NRR (SF) is subtracted from the A-weighted noise exposure to provide the protected exposure level:

Protected dBA = unprotected dBA – NRR(SF).

If the C-weighted noise exposure level is used, a 3-dB adjustment is made to account for predicted differences in the A and C levels (recent re-evaluations of the noise databases that were used to developed the NRR (SF) found the A- versus C weighted difference to be 3 dB, not 5 dB and not 7 dB).

Protected dBA = unprotected dBC -3 dB – NRR(SF).

Where can I find the NRR(SF)?

The adoption of the initial version of ANSI S12.6 in 1997 as the standard that replaced ANSI S3.19-1974 did not change the regulatory requirements that all protectors sold in the United States be labeled with the NRR as described above and obtained by testing according to the experimenter-fit method of ANSI S3.19-1974. After ANSI 12.6 was adopted and ANSI S3.19 was rescinded, many hearing protector manufacturers began testing their products in accordance with Method B, the subject-fit method. However, only a few manufacturers have released the data. As other jurisdictions outside of North America have started to demand data from testing procedures similar to Method B of ANSI S12.6, many companies have complied. The NRR(SF) is used in Brazil, Australia, and New Zealand. Every HPD sold in Brazil is tested by an approved Brazilian laboratory by Method B of ANSI S12.6-1997 before the HPD may be sold in Brazil. Australia and New Zealand require every HPD sold in those countries to have been tested by Method B and then labeled accordingly with the NRR(SF), but the testing may be done by a laboratory anywhere.

A search of the Internet or direct inquiry with the company may result in access to Method B data and a value similar to the NRR(SF). The NIOSH online Hearing Protector Device Compendium lists most of the HPDs sold in the United States and shows the NRR(SF) for many of them. The Compendium also lists the Internet website for almost all the manufacturers, which may provide more information.

Can I legally use the NRR(SF)?

Yes. OSHA has recognized the NRR(SF) as an alternative the NRR as another way to apply a safety factor to the NRR.

If you are considering two devices, one of which has both an NRR and NRR(SF), select the device with the NRR(SF) and apply it to the equations above to determine if it can provide adequate protection.

The best value for protected level is between 70 and 80 dBA. A protected level of less than 70 dBA indicates potential over protection. A person who is overprotected may be isolated from the larger acoustic environment, unable to hear warning signals and fellow workers. As such, the overprotected worker can be a safety hazard. There are reports of workers being injured and killed because they were unable to hear warning signals or the sound of approaching vehicles because they were wearing HPDs that provided too much attenuation. The primary complaint that workers have reported about used HPDs are that they can’t hear fellow employees talking to them and that they can’t hear their equipment. It isn’t unusual to see a worker lift an earmuff cup or remove an earplug to talk with a fellow worker, and then replace it, a type of action that undoes the effectiveness of the HPD. Carefully selecting HPDs to avoid overprotection could also ameliorate the hazard potentials and worker attempts to work around using HPDs.

If the protected value is above 80 dBA, the worker will be under protected. Under protection can result in the development of NIHL despite using the HPD.  NIHL is insidious. It starts gradually and will generally go unnoticed until the hearing loss begins to interfere with communication. NIOSH’s definition of material hearing impairment (Franks, et al., 1998) is such that a person can suffer a change in hearing up to the point of developing a material impairment without noticing any change in day-to-day auditory function. Beyond that point, the hearing loss becomes an impairment. NIHL will usually cross the line from loss to impairment within the first five years of exposure. It is often observed that under protected workers develop NIIHL.

Any hearing loss prevention program that relies upon the NRR(SF) instead of the NRR and insures that workers are neither under or over protected will be successful in preventing NIHL and will have no problems with OSHA nor another other regulatory agency.


References

American National Standards Institute. (1974) American National Standard for the Measurement of Real-Ear Hearing Protectors and Physical Attenuation of Earmuffs. ANSI S3.19-1974, American National Standards Institute, New York, NY.

American National Standards Institute. (1997) Methods for Measuring the real-ear attenuation of hearing protectors. ANSI S12.6-1997 American National Standards Institute, New York, NY.

Berger, E.H., Franks, J.R., and Lindgren, F., International Review of Field Studies of Hearing Protector Attenuation, In A Axelsson (Ed), Scientific Bases of Noise-Induced Hearing Loss, Chernow Editorial Services, Inc, New York, 1996

Environmental Protection Agency. (1979). 4 0 CFR Part 211 – Product noise labeling, Subpart B – Hearing protective devices. 44 Federal Register 56139-56147.

Franks, JR. Merry, CJ Stephenson, MR, Themann, CL, Prince, MM, Smith, RJ, Stayner, LT, and Gilbert.SJ (primary authors) Chan, HS (document manager). Criteria for a Recommended Standard: Occupational Noise Exposure, Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHHS (NIOSH) 98-126, Cincinnati, OH (1998)

Johnson DL and Nixon CW (1974) Simplified methods for estimating hearing protector performance. Sound and Vib 8(6):20-27.

Kroes P, Fleming R; Lempert B. (1975). List of personal hearing protectors and attenuation data, NIOSH Technical Report, HEW Publication No. (NIOSH) 76-120.

National Institute for Occupational Safety and Health (2016) Hearing Protective Device Compendium. https://www.cdc.gov/niosh/topics/noise/hpdcomp/.

Royster LH. (1995). In search of a meaningful measure of hearing protector effectiveness; Recommendations of the NHCA’s task force on hearing protector effectiveness. Spectrum 12(2):1, 6-13.

U.S. Department of Labor, Occupational Safety and Health Administration. (1983). Occupational Noise Exposure: Hearing Conservation Amendment; Final Rule. 48(46) Federal Register 9738-9785.

U.S. Department of Labor, Occupational Safety and Health Administration. (1983). 29 CFR 1910.95(b)(1), Guidelines for Noise Enforcement; Appendix A.

U.S. Department of Labor, Occupational Safety and Health Administration. (2016). OSHA Technical Manual: https://www.osha.gov/dts/osta/otm/new_noise/index.html

[i] Time Weighted Average –The permissible exposure limit (PEL or OSHA PEL) is a  legal limit in the United States for exposure of an employee to a chemical substance or physical agent such as loud noise. A PEL is usually given as a time-weighted average (TWA), A TWA is the average exposure over a specified period, usually a nominal eight hours. For noise, the PEL is a TWA8 of 90 dBA with an excursion limit of 115 dBA. The TWA involves a trading ratio of time and intensity, which for noise is 5 dB so that the allowable exposure time doubles or halves as the sound level decreases or increases by 5 dB.


These articles were written for ProtectEar by Dr. John R. Franks, former Chief of the Hearing Loss Prevention Section of the Department of Health and Human Services, U.S. Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Cincinnati, OH

If you’ve missed any articles in the series let us know.  

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NIOSH HAS DEVELOPED A SOUND LEVEL METER MOBILE APP DESIGNED TO MEASURE NOISE EXPOSURE IN THE WORKPLACE.

February 1, 2017

 

NIOSH has developed a sound level meter mobile app designed to measure noise exposure in the workplace.

The app, available for Apple devices, provides noise exposure metrics that are of “importance for proper occupational noise measurements,” NIOSH states in a Jan. 17 blog post. NIOSH is collaborating with other agencies to develop an Android version, but the agency stated that it may verify the app only on selected devices because of the large number of available Android devices and models. The project would begin when funding becomes available.

The app supplies instantaneous sound levels in A-weighted, C-weighted or Z-weighted decibels, as well as parameters intended to aid with lowering occupational noise-induced hearing loss. Users can save and share measurement data and receive general information about noise and hearing loss prevention.

NIOSH recommends using the app with an external microphone and acoustical calibrator for better accuracy. The app is not intended to be used for compliance or as a substitute to a professional sound level meter or a noise dosimeter, the agency cautions.

In 2014, NIOSH researchers examined nearly 200 sound measurement apps. They found that most available apps are designed for the casual user and do not have the accuracy and functionality for occupational noise measurements, according to the blog post.

NOISE AND HEARING LOSS PREVENTION

 Close-up of downloaded Sound app.

The NIOSH Sound Level Meter mobile application is a tool to measure sound levels in the workplace and provide noise exposure parameters to help reduce occupational noise-induced hearing loss.

Key Benefits

  • Raises workers’ awareness about their work environment
  • Helps workers make informed decisions about the potential hazards to their hearing
  • Serves as a research tool to collect noise exposure data
  • Promotes better hearing health and prevention efforts
  • Easy to use

2017 is not just another year, it’s the year of Hearing Loss Prevention.

January 25, 2017

2017 is not just another year, it’s the year of Hearing Loss Prevention.

Make the most of your hearing health in 2017

New hearing technologies and increased awareness of hearing loss points to 2017 as being the “Year of the Ear.” If you haven’t already made your New Year’s resolutions, consider what you can do to protect your hearing and be more hearing health conscious. We’ve compiled a list of a few things that you might want to consider for the new year.

Hearing Health & Loss Prevention

Hearing loss prevention is an action where you take special precautions to ensure your hearing is not being negatively affected. Sometimes the loss itself can be difficult to identify, which is why it’s so important to be on top of changes that may occur to your hearing.

Your hearing health has a direct effect on your overall health. Hearing loss has been linked to numerous medical issues, including viruses, bacteria, heart conditions or strokes, head injuries, tumors and certain medicines.

  • Heart health: Studies show that a healthy cardiovascular system – a person’s heart, arteries and veins – has a positive effect on hearing. Inadequate blood flow and trauma to the blood vessels of the inner ear can contribute to hearing loss.
  • Hypertension: There is a significant association between high blood pressure and untreated hearing loss. Hypertension can be an accelerating factor of hearing loss in older adults.
  • Smoking: Current smokers have a 70 percent higher risk of having hearing loss than non-smokers.
  • Obesity: Higher body mass index (BMI) and larger waist circumference are associated with increased risk of hearing loss in women.
  • Diabetes: Hearing loss is twice as common in people with diabetes compared to those without. Adults whose blood glucose is higher than normal but not high enough for a diabetes diagnosis, have a 30 percent higher rate of hearing loss compared to those with normal blood sugar.
  • Ototoxicity: There are more than 200 medications (prescription and over-the-counter) on the market today that are known to be ototoxic or “poisonous to the ears.” Some known ototoxic drugs are: Aspirin, Quinine, Loop diuretics (or “water pills”), certain antibiotics, and some environmental chemicals.

Make sure you are making an annual hearing test part of your hearing health routine. Many hearing clinics provide free testing. If you haven’t already, schedule your next evaluation for the new year today.

Protect Your Ears

Noise-induced hearing loss (NIHL) is increasingly becoming a problem, especially for people aged 12 to 35. With the growing popularity of personal listening devices, taking steps to protect your hearing has never been more important. Take steps to ensure that you are listening at an appropriate volume, and use earplugs in heavily noise-polluted environments such as sports venues, hunting, shooting, concerts, or other events and activities that are loud. As little as 10 seconds at a loud stadium or concert can cause permanent hearing damage. Learn More about Hearing Protection.

Take Steps to Treat Hearing Loss

A shockingly large number of people that could benefit from using hearing device don’t use one. Hearing aid technology has improved significantly in recent years, and it’s worth exploring what kind of solutions there are that could make your life easier. You might be surprised by what a hearing aid device can do to improve your quality of life. If you’re suffering from hearing loss and haven’t considered treating it, now is the time!

Don’t Be Afraid to Ask for Help

Every person’s hearing is unique, almost like a fingerprint. When it comes to issues like hearing loss, tinnitus, hearing technology etc. don’t be afraid to ask a professional for advice. Your audiologist can help you make informed decisions about your hearing health and start on a path toward better living.

With the New Year here and moving with a vengeance, it is important to be proactive especially where your health is concerned. Whether it is your hearing, or a colleagues hearing, please educate and pass this message on.

Let’s prevent Hearing Loss, one ear at a time.dB Life Sleeper

 

Canada: Large disparities between measured and self-reported hearing loss

January 20, 2017

One in five Canadians aged 20 to 79 was found to have a hearing loss in at least one ear when tested audiometrically. Among those aged 70 to 79 the figure was 65%. Overall less than 4% reported themselves to have a hearing loss.

Canada: Large disparities between measured and self-reported hearing loss

Almost one in five Canadians aged 20 to 79, an estimated 4.6 million adults, was found to have a hearing loss in at least one ear when tested audiometrically. Among those aged 70 to 79 the figure was 65%.  Fewer than 4% of the adults reported having a hearing loss themselves. This is the result of a Canadian study published in Health Reports, which shows large disparities between self-reported and measured prevalence of hearing loss.

Mild hearing loss is rarely self-reported

12% of the Canadian adults were found to have a mild hearing loss. These people would be less likely to be aware of or self-report their hearing difficulty and would cope by using adaptive measures such as moving closer to the source of the sound or increasing the volume. For 7% of adults, hearing loss was moderate or severe.

In Canada, the prevalence of hearing loss has typically been estimated through self-reports. However, self-reports may result in underestimates, especially among older adults and among people with mild hearing loss or high-frequency hearing loss.

10.4 million with hearing loss by 2036

According to the study, the number affected is likely to rise substantially in coming decades and is projected to double from 5 million in 2011 to 10.4 million by 2036.

Despite the fact that the study results show a significant number of hearing impaired Canadians, the prevalence of hearing loss may still be underestimated. The study used both collected audiometric and self-reported data from the Canadian Health Measures Survey which only includes data of the population aged 20-79. People aged 80 or older is not included in the data and hearing loss is known to be more common with age.

Read the study

Source:www.statcan.gc.ca

How Important is Proper Fitting for Your Personal Hearing Protection Device?

January 17, 2017

Just How Important is Proper Fitting for Your Personal Hearing Protection Device?

Whether you wear a personal Hearing Protection Device (HPD) in your work environment or for recreational activities just how important is proper fitting for your personal hearing protection device?

With so many options on the market for styles of hearing protection ranging from a simple ear plug to very detailed styles of Custom Protect Ear’s moulded or 3D produced personally fitted HPD’s, how do you choose which is best for your hearing protection?  Do you choose simply on the sophistication or level of the noise cancelling aspect or does proper fitting also factor in to your decision.

Let’s examine how proper fitting can enhance your experience and protection.

The number one indicator of how effective a HPD will be is if you actually wear it!!!

If your HPD is not comfortable will you be less likely to wear it or want to wear it? If you do wear it but because of improper fitting it is less effective than you assume it will be, you will not achieve the protection level you may need.

According to a publication in The National Institute for Occupational Safety and Health (NIOSH), they state that

“Hearing protection devices (HPD’s) often fail to protect workers from hearing loss because of poor fit.” 

In fact NIOSH was so concerned over the effects of poorly fitting HPD’s that they developed and licensed a system to create a fast and reliable fit-test system that measures the amount of sound reduction an individual worker receives from the HPD and identifies workers that are not sufficiently protected.

Hearing Protection Device

What are some concerns with improperly fitting HPD’s?

  1. If your HPD is uncomfortable will you be more likely to remove it for periods of the time you need protection.
  2. Will you be more likely to be distracted by the discomfort it is causing and be more aware of your discomfort than you are on your job or activity? Could you suffer from headache or earache induced discomfort from an improper fit?
  3. If moisture is trapped in your ear with not enough air circulation could this lead to an increase in ear infections with possible infection induced damage?
  4. If your HPD’s are designed to be able to hear communications or certain noises or sounds, would that communication level be reduced or hindered with improper fit? Would this encourage the user to possibly remove the HPD so that they can hear that communication leaving them open to noise induced hearing damage?
Personal Hearing Protection Device

Have you or your Employer taken the steps to incorporate fit testing into your hearing protection plan? If not, start today! Ask about FitCheck Solo 

With the properly style of hearing protection device based upon your particular needs and the proper fitting of that device you can dramatically increase your hearing protection, and isn’t that what you would expect from your HPD?

DRIL-COM – A new way for evaluating hearing protectors

January 11, 2017

DRIL-COM – A new way for evaluating hearing protectors

When trying to determine whether a hearing protection device (HPD) can be effective for use in a given noisy environment, the conventional method has been to examine attenuation using SNR(SF84), its NRR(SF), or its derated NRR. Going to extremes, the individual mean octave-band attenuation values might be compared to the octave-band levels of the noise of concern to determine what the Assumed Protective Value (APV) might be with some allowance for the reported standard deviations of the attenuations.

All of these values will shed light on how effective the HPD should be in reducing potentially harmful noise to a safe level under the HPD. However, none of these values shed any light on how useable the HPD is in allowing the wearer to maintain environmental awareness. In construction, in  manufacturing, and in the military, being aware of what’s happening in the surrounding areas can be as important to personal safety as the HPD is to the prevention of noise-induced hearing loss (NIHL).

Historically, when those who are supposed to use HPDs are asked why they don’t or won’t, the rank ordering of reasons is:

  • Interference with their ability to hear speech of other workers or team members;
  • Inability to hearing warning signals;
  • Inability to hear what is going on around them;
  • Inability hear the equipment that they are using; and
  • Comfort, or lack of it including heat buildup for earmuffs.

Those top five reasons can be lumped into one category:

Reduction of necessary auditory awareness.

For the military, auditory awareness is critical for troops in combat. Each soldier or marine leaving for a combat zone is issued, at present, the 4th generation of the so-call . It is a multi-flanged, premolded earplug with a passage through its center that passes through an acoustic filter that is supposed to have little effect for sound levels below 120 dB SPL and then increase in attenuation as the sound level increases.

combat ear plugs

The technical label for this technology is non-linear passive level-dependent. This technology has been around for decades and was first developed and tested by ISL in France. Ideally, an HPD such as the Combat Arms earplug would have no effect on auditory awareness for most signals.

Similarly, there are HPDs that are powered, either by their own battery or from a battery pack worn by the user that powers the HPD as well as other equipment. The technical term for theses HPDs is non-linear active level-dependent. The word “active” applies to the use of a powered electric circuit that passes all sound from the outside world into the ear of the wearer and then adjusts its gain or volume as the level of the outside sound increases until cutting off. Once cut off, the wearer experiences the full passive attenuation that the HPD provides. These types of devices are very popular among shooters and hunters in non-military applications. It is presently unclear about their deployment for military use.


DRIL -COM – The Research Case Study

Dr. John Casali at Virginia Tech University (VTU) has been a strong proponent of the importance of the auditory awareness effects of HPDs. There are reported incidences every year of workers who are hurt by equipment because their auditory awareness was impaired by the HPD they were wearing. These accidents include being run over by fork lifts, being run into by robotic parts delivery vehicles, and being hit by moving materials, such as delivered by crane at construction sites. All due to an HPD-induced inability to hear the necessary auditory cues that would have allowed them warning to get out of the way. For the soldier in combat who is using an HPD, the inability to clearly hear the approaching of what could be enemy personal, to hear the bolt noise from a rifle or the sliding in of an ammunition magazine, or even to hear the retort of a weapon fired at a distance can be life and mission endangering.

After years of work on auditory awareness issues for the larger employment universe, Dr. Casali focused on setting up a proof-of-concept project to show how to determine the effect of HPDs on auditory awareness. The method was given the name DRIL-COM, with each of the letters in the first word having meaning:

  • D – Detection.
    • The ability of the HPD user to even detect the presence of a sound either in quiet, in the presence of low-level background noise, or the presence of high-level background noise.
  • R/I –
    • Recognition/Identification. The ability to determine what made the sound. The reaction to a friendly sound should be different that the reaction to an unfriendly sound. Consider the swishing of reeds against each other as one fellow soldier returns from the latrine verses the sound of a magazine being slipped into an AK-47 by an unfriendly. Once a sound is detected, it must be recognized correctly and quickly.
  • L- Localization.
    • The last step of DRIL is localization, the ability to quickly determine the direction from which the sound came. In the case of a worker trying to avoid being run over, it’s ­important to know from where the sound of the approaching vehicle came. For the soldier, it’s important to know from where came the sound of the magazine being slipped into a weapon before break out of a fire fight.
  • COM – Communications.
    • Though not a letter, it is just as important. Each HPD has its own impact on communication, particularly in the presence of background noise. The COM portion of DRIL-COM evaluates that.

How was DRIL-COM administered?

In a large space to be as acoustically dead as possible so that all signals generated by the system could arrive at the listener without dealing with room reflections.  Further, the technique was administered computer software and electronics. However, nothing was so specialized that it couldn’t be easily replicated by another laboratory; it is not ready for field deployment just yet.

The HPDs tested were:

3M 4th Generation Combat Arms™ earplug in the open setting, INVISIO X50™, Nacre-Honeywell Quiet Pro+™, Peltor Con Tac III™, Etymotic EB15LE™. Performance for all the HPDs was compared to ears open with no HPD.

What the results showed, in general, was that there was no HPD that was as effective in all the DRIL-COM categories as the open, unprotected ear. While each HPD provided some degree of protection from noise, none allowed the critical elements of auditory awareness to be as effectively managed as ears open with no HPD. Unfortunately, soldiers appear to have figured this out for themselves. Of those going into combat in Afghanistan who were issued the Combat Arms earplug, 30% have come back with NIHL (Noise Induced Hearing Loss)  that they did not have upon deployment BECAUSE THEY DID NOT USE the earplugs as they needed to maintain auditory awareness.

Of interest was the final combined ranking of the tested HPDS in the DRIL-COM testing. Worse were the Combat Arms earplug, the Quiet Pro max and the Quiet Pro when set to unity gain. Max is when the gain of the HPD is set to full on, which is possible with active non-linear HPDs. Unity gain means that the sound level outside the HPD is the same as inside.  These three HPDs (settings) were statistically significantly worse than all the other HPDs tested in all conditions. Following, and statistically different from ears open but not from each other, were Com Tac III unity, Com Tac III max, X50 unity, X50 max, EB15LE unity, and EB15LE max.

So, what’s the take away message from the DRIL-COM tests.

First is that there is a method that can be deployed to determine the impact of an HPD on auditory awareness. It is not a method that an end user can deploy easily, but it is one that a testing laboratory or manufacturer could set up and run and then assign a number for auditory awareness to their product. Further, manufacturers could work to make sure that their HPDs have as little impact on auditory awareness as possible.

“This is why only dB Blockers double-vent their protectors when connecting a radio to them”.

Clearly, for the worker who needs 25 dB of protection this may not be important or possible. But, since most workers need 15 dB or less of protection in most situations, and in some need none but work in fluctuating noise levels, auditory awareness may become more important in selecting an HPD than mere attenuation.

Second, at present, almost anything that is stuck in the ear or placed over it tends to interfere with auditory awareness. Prior to the late 1970s the pinna (outer ear) was thought to be a vestigial organ. It sits on the side of the head, it is immobile, and best for holding eyeglasses aear2nd decorating with earrings. But it proved to not be case. The pinna is a critical organ for auditory awareness.

It allows the listener to locate origins of sounds in space, it enhances high-frequency hearing, and the central auditory system has learned how to use it. No two pinnae are quite alike, however, and so it is difficult to develop a universal surrogate that can be incorporated into an HPD.

Case in point is the Combat Arms earplug.

In its open condition, it is simply a tube with a small filter in in that is not supposed to effect low-levels of incoming sound. At face value, it would seem to be the best solution. But the DRIL-COM testing showed it to be the composite worst. Its alternation of the pinna’s acoustics, even though the HPD was deeply inserted.  On the other hand, the EB15LEE, which is an active earplug, seemed to be the least destructive in both its unity and max settings. It is a digital processing system that might be further taxed to calculate the harm it has caused ear acoustics simply by its insertion and then develop a new algorithm to make the EB15LE effectively acoustically invisible. That type of protector could take into account the natural acoustics of the pinna and further undo its deleterious effects until it was neutral in both of its setting, unity and max.

For a passive non-linear HPD to be effective in terms of auditory awareness, it would have to be deeply inserted so that is outer surface was inside the ear canal, much like and completely-in-the-ear canal (CIC) hearing aid, but then it would be difficult to use in both the open and closed settings as the Combat Arms earplug is. There is possibly a solution available, but it would need to be submitted to a DRIL-COM test protocol to prove it.


READ MORE ABOUT THE DRILCOM REPORT 

Whitepaper

ABSTRACT

The Virginia Tech Auditory Systems Laboratory (ASL) research effort for the DoD Hearing Center of Excellence was aimed at the development of an efficient, in- laboratory implementable test battery for auditory situation awareness (ASA) that objectively quantified the ASA performance afforded by various Tactical Communications and Protection Systems (TCAPS) and augmented/advanced Hearing Protection Devices (HPDs) used by the U.S. military. Specifically, each of the fundamental ASA task elements of Detection, Recognition/Identification, Localization, and COMmunications, hereafter termed “DRILCOM” ASA elements, was measured in the psychophysical test battery that was the primary deliverable from the research. The individual ASA elements’ scores from the test battery were kept separate so that performance on each element of ASA could be ascertained, and via statistical analysis, the individual elements’ sets of scores were applied to determine the DRILCOM test battery’s effectiveness in measuring ASA afforded by each TCAPS or augmented HPD. The intent was that the test battery would ultimately be deployable in a military audiology clinical or other similar laboratory setting, and applicable to a wide variety of TCAPS and HPDs.

Does Your Law Enforcement or Emergency Response Job Expose You to Hearing Loss?

November 21, 2016

Law Enforcement or Emergency Response Job & Hearing Loss

Your job is to help and protect the community in which you live but does your Law Enforcement or Emergency Response job expose you to Hearing Loss? Are you the one who needs help and protection?

If you are in Law Enforcement, First Response teams of Police, Fire Fighting or Ambulance are you exposed to high levels of noise that can cause hearing damage? What steps can you and your governing authorities take to ensure your hearing is protected from on-the-job damaging sounds, sirens and high decibel sounds from weapons related devices?

Firefighters File Lawsuits about Hearing Loss Fire fighter and hearing loss

For more than a decade Firefighters have been filing lawsuits against an Illinois-based company that makes sirens. The claims have centered around the concerns that the company that makes sirens did not do enough to design the fire trucks in a way that would shield the Fire Fighters from sound blasts that reach 120 dB. Noise in the range of 120 dB would be equivalent to the noise from a jackhammer about 3 feet away and can cause pain and according to both OSHA (Occupational Safety and Health Administration) & NIOSH (The National Institute for Occupational Safety and Health) that level is outside of any time length of exposure for hearing safety. In other words, it is at a daily permissible noise level of 0 minutes!

Exposure to noise (Hearing Loss) from Weapons, support vehicles and equipment

What about Law Enforcement, Military, Security or Correctional Officer jobs? Not only are you exposed to noise from the sudden discharge of weapons related devices but you could also be exposed to noise from Helicopters, sirens from emergency support vehicles and equipment. A jet engine at 100 feet can emit 140dB of noise, a Military Jet Aircraft take-off from an aircraft carrier with afterburner at 50 feet can create 150dB of noise, a 12 Gauge Shotgun blast at close quarters can be as high as 165dB!

Military Jet

Personal (Custom) Hearing Protection Devices (HPD’s)

Most Governmental Workers exposed to noise are supplied HPD’s for use on the job. The importance of HPD’s is that they are the correct style of protection for the environment you will be in. You will need a different hearing protection device for the firing range where the focus will be on as much protection from noise as possible with less need for being able to hear commands or instructions. While on-the-job as a Law Enforcement Official in a situation where there is a strong possibility of weapons being fired, you would require a HPD that is instantly attenuated for gun fire but allows for certain necessary sounds to be heard such as interpersonal and radio communications or equipment.

Are you exposed to these high levels of noise on the job? Are you supplied and correctly using a personal hearing protection device that provides you the correct protection throughout your day? Have you been properly trained in its effective use?

Warning signs of hearing loss

Be aware of what the warning signs of hearing loss are. Understand that tinnitus or ringing in the ears may not be the sound of your background environment but may actually be the beginning signs temporary leading to permanent of hearing loss. Hearing loss due to damage is not reversible and in fact may lead to further damage as your loss of hearing may be causing you to turn up the volume of TV’s, music devices or phones. Recognize that hearing loss may also take the form of selective hearing loss of certain frequencies of sound. You may not hear high pitched sounds of a female or child’s voice but still be able to clearly hear the low pitched sound of a man speaking.

Take caution in your job and protect not only the public in your service oriented career but also take care to protect yourself and your valuable asset of hearing. Learn more.. 

Tips To Keep You & Your Ears Safe This Halloween

October 31, 2016

Tips To Keep You & Your Ears Safe This Halloween

With halloween around the corner here are some useful ways to enjoy the evening while keeping you and your ears safe!

 

Bonfires & Fireworks What You Need To Know

If you are planning on attending a bonfire, make sure to enjoy from a distance. Keep well back from where the bonfire and fireworks are being set off. The noise and smoke pollution could irritate a pre-existing hearing condition, including tinnitus.

 

 

Children hearing and safety tips

Give your kids flashlights and apply reflective tape to costumes and treat bags to help pedestrians and drivers see your children.

A child’s hearing is particularly sensitive to loud noise. Protect your child’s hearing from any loud noises particularly during halloween where the noise generated from fireworks and bangers can be similar in decibel range to gunshot blasts. This can cause serious hearing damage, especially in young children up to the age of five, whose hearing is more sensitive than adults.

 

Warm Ears Are Happy Ears

Ear warmers are a staple in any autumn/winter wardrobe, especially when going out and enjoying a long walk through the leaves, but the winter wind is always whipping around and can irritate your ears, so wrap up warm with ear warmers or ear muffs.

Keeping Your Ears Safe Around Fireworks

Noise from exploding fireworks can reach a massive 150-175 decibels! The World Health Organisation recommends that adults not expose themselves to more than 140 dB of peak sound pressure. If you have children, the recommendation for them is 120 dB. Exposure to loud noises such as fireworks can cause tinnitus, hearing loss, or aggravate your existing tinnitus.

If you will be around fireworks this weekend, make sure to wear adequate hearing protection.

 

Everyone loves a party

If you’re hosting a party this Halloween be mindful of friends with hyperacusis, or other hearing problems and barriers that might make it difficult for friends to enjoy the night.

Tip:

  • Have a quiet room at your party for people who want to have a conversation in a quieter environment.
  • Rooms should be well lit so that those who need to lip read can follow the conversation.
  • Don’t play the music too loud, have it a volume that won’t damage your guests hearing. Even those who don’t have hearing related problems.

Pet Friendly Halloween

Pets can be very anxious around this time of year with the loud noises that come with Halloween.

Tip: When fireworks and other loud noises happen suddenly, don’t fuss as your pet may pick up on your anxiety making the problem worse. Reassure your dog vocally with a positive tone when he is frightened. Do not punish the pet when they are scared, this only confirms that there is something to be afraid of. Maybe try to engage your pet in some form of active game.

Cats prefer to be left to cope on their own but make sure they have access to a safe zone they normally like to retreat to, and try to keep your cats in a few days before and after Halloween night. Black cats are especial prone to cruelty-related incidents.


All forms of chocolate especially dark chocolate are dangerous for dogs and cats, so remember to keep it out of their reach. Keep pets confined and away from the door. Not only will your door be constantly opening and closing on Halloween, but strangers will be dressed in unusual costumes making lots of noise. This, of course, is scary for our furry friends.

Have a great Halloween weekend, be sure to share your tips with us below or via our social media accounts

 

Canucks For Kids Fund 

September 15, 2016

vancouver_canucks_logo_3956

CPE raises funds for Canucks For Kids Fund (CFKF) through the sale of their Canucks branded dB Blocker™ hearing protectors.

Custom Protect Ear (CPE) will donate $5 to CFKF from every sale of their Canucks-branded dB Blocker™. The Canucks for Kids Fund dedicates resources to assist charities which support children’s health and wellness, foster the development of grassroots hockey, and facilitate and encourage education in British Columbia.

canuck-blockers-webCPE also supplies the Vancouver Canucks with hearing Protectors for use by the Canucks NHL and AHL players and members of their management.

As North America’s largest personalized industrial hearing protector manufacturer, hearing conservation is CPE’s only business. In every workplace, sporting, entertainment or home environment CPE helps protect you from noise induced hearing loss. To get Canucks-branded dB Blockers™ contact us today! 


For more information regarding dB Cares™, or how we both might become better partners in cause related initiatives, call or email us.

We’d love to hear from you.