Page 23 - Occupational Health & Safety, September 2017

Thanks to the broader band noise reduction offered in the ear canal, the active portion adds more than three times the allowable ambient noise exposure time compared to double hearing protection.
more rapidly as noise levels increase.
Many manufacturers and consultants will offer services to help you determine the most appropriate hearing protection for your specific occupational environ- ment. The first step will be to carefully evaluate the noise environment at relevant occupational locations. The most sophis- ticated and accurate methods will include evaluation of the spectral content of the noise field, levels, and durations of expo- sures. These noise measurements can then be evaluated against candidate hearing pro- tectors to predict their effectiveness. The
This miniaturized approach to in-the- ear active noise reduction provides the benefit of a wider frequency range of at- tenuation, up to 2 kHz in some cases. You may have read about active noise reduc- tion only attenuating at frequencies below about 600 Hz. This is a physical limita- tion experienced by circumaural headset implementations of active noise reduction technology. The combination of micro- phone proximity to the eardrum and the smaller acoustic volume between the ear- drum and the ear plug means higher fre- quencies can now be attenuated. Thanks to the broader band noise reduction of- fered in the ear canal, the active portion adds more than three times the allowable ambient noise exposure time compared to double hearing protection. Triple hearing protection keeps your employees safer for longer while increasing productivity, pre- venting permanent hearing loss, and im- proving morale in the workplace.
Evaluating New Technologies
There are always important limitations that should be considered when evalu- ating hearing protection options incor- porating new technologies. The triple hearing protection approach described above cannot be duplicated with an ANR circumaural headset combined with an ear plug. The ANR effectiveness becomes isolated to the external ear when the ear plug is inserted into the canal, offering no added benefit to the overall hearing pro- tection performance.
Additionally, environmental situational awareness can be compromised by over- protection. A balance must be struck be- tween providing adequate hearing protec- tion without diminishing other aspects of occupational safety.
When to Use Triple
Hearing Protection
So when should you consider fitting your employees with triple hearing protection? A general rule of thumb is this: When your employee is exposed to an eight-hour time weighted average noise level of 115 dB(A) or more, you should consider triple hear-
ing protection. Although OSHA continues to recommend an exchange rate of 5 dB (an increase of 5 dB results in a halving of al- lowable exposure time), much of the rest of the hearing conservation community rec- ognizes that 3 dB is more appropriate. Tri- ple hearing protection becomes even more relevant in the context of a 3 dB exchange rate because allowable exposure times drop
www.ohsonline.com
Experience the benefits of the Dräger X-plore® 8000
with a 90-day free trial.
The Dräger X-plore® 8000 Powered Air-Purifying Respirator stands up to the harshest environments.
Challenging workplace conditions demand reliable solutions. The new Dräger X-plore® 8000 offers rugged design, intuitive operation, and a superior fit to keep your team safe and focused. Now, for a limited time, discover just how innovative this respirator is with a free, 90-day trial. Terms and conditions apply. Call today for more info.
LEARN MORE ABOUT THE 90-DAY FREE TRIAL AT 1-800-4DRAGER
Circle 2 on card. 23
6679