96052VSHearing Protection Online Resources

CAOHC – Council for Accreditation in Occupational Hearing ConservationCouncil for Accreditation in Occupational Hearing Conservation's

  • Determining When Hearing Loss is Work Related (77KB pdf)
    This hearing protection article will outline some of the pertinent issues relating to work-relatedness determinations, including the responsibilities of the OHC and the PS.

Occupational Noise Surveys

This is a technical document that gives details on how noise surveys should be performed and how the results should be reported. See also the companion document, Basic Noise Calculations. WorkSafeBC * PDF (675 KB) Updated: April 2007

Canada Occupational Health and Safety Regulations 

Canadian Centre for Occupational Health and Safety

The Canadian Hearing Society

Decibel Comparison Chart (Download PDF) 



Hearing Protection Articles

Solving the Noise Induced Hearing Loss Problem by Asking the Right Questions: Part One of a Two Part Series

Let’s examine why we haven’t made more progress eliminating NIHL. It starts with the history of noise as an industrial hazard. The history of hazardous noise is well defined. As early as the beginning of the last century, noise was recognized as an industrial hazard.

Solving the Noise Induced Hearing Loss Problem by Asking the Right Questions: Part Two of a Two Part Series

Last issue we explored the problem of noise induced hearing loss (NIHL). We discovered that labelling the potential protective capability of a hearing protector on the packaging did not aid in reducing NIHL. We also discussed how the industry had fixated on the fitting of the protector to the ear only to discover situations where attempting to maximize the fit didn’t solve the problem. In fact, we’re no closer to a solution even though we have 30-plus years of developing a better understanding of the problem. Certainly discovering how to reduce or eliminate NIHL is a real conundrum.

Alternative Field Methods for Measuring Hearing Protector Performance (115K pdf)
In comparison with the mandatory noise reduction rating (NRR) testing of every hearing protector sold in the United States, real-world tests of hearing protector attenuation are scarce.

Development of a New Standard Laboratory Protocol (772K pdf)
Development of a new standard laboratory protocol for estimation of the field attenuation of hearing protection devices: Sample size necessary to provide acceptable reproducibility.

Personal Hearing Conservation Measures (184K pdf)
Evaluation of the workplace for noise exposure includes preliminary noise measurements, separation of the workplace into different noise risk areas – and development of both short and long term noise management plans. After evaluation of the workplace, it might be appropriate to evaluate possibilities which the individual employee has to control his or her own (noise) work environment and to evaluate simple measures which may result in a further reduction of the noise level.

Hearing protection attenuation Is more really better? (565K pdf)
When choosing hearing protection, people tend to look at Table lA in Canada’s hearing protection standard and declare that Class A protectors must be the best because they offer the highest attenuation — end of discussion. But this approach is full of problems, not the least of which is its potential to discourage the use of hearing protection.

Earlog 20 – The Naked Truth About NRRs (55K pdf)
Since hearing protection devices (HPDs) are worn primarily for the purpose of noise reduction it is not surprising that hearing conservationists place great significance upon the sound attenuation that such devices can provide.

The Ardent Hearing Conservationist (66K pdf)
It all seems pretty straightforward. Noise damages hearing. Hearing protectors block sound. Select devices with high, or at least adequate Noise Reduction Ratings (NRRs). Hand them out. Tell people they need to wear them. Require they be worn. Job done. Well, not exactly …

How loud is too loud? Warning Signs Your Workplace May be Too Noisy  (991K pdf)
Exposure to high levels of noise can cause permanent hearing loss, and each year approximately 30 million people in the United States are exposed to hazardous noise in the workplace.

Measurement of Insert-type Hearing Protector Attenuation on the End-user: A Practical Alternative to Relying on the NRR. 

Hearing protectors are labeled with a Noise Reduction Rating (NRR) that is derived from laboratory measurements of the attenuation provided to trained and motivated human subjects in a ‘sterile’ environment. As intended, these measurements represent a best-fit condition. The literature indicates that the average attenuation provided to end-users of hearing protectors is often only a fraction of the labeled values. Because of this, various derating schemes are employed, including the 50% derating suggested in the OSHA inspector’s Technical Manual and the variable derating according to protector-type suggested in the 1998 NIOSH criteria document on occupational noise exposure.

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