Hearing Protector Calculator

Calculate Maximum Allowable Noise Exposure using Hearing Protector NRR

This calculator provides a maximum allowable time-weighted average noise exposure estimate based on the laboratory Noise Reduction Rating (NRR) for a specific hearing protection device. This estimate is used to determine compliance for hearing conservation purposes according to OSHA 1910.95(j).

It is important to know that even if a maximum allowable time-weighted average is acceptable according to the OSHA formula, real world results may vary for any given individual. Therefore, Individual Fit Testing is considered best practice for understanding hearing protection attenuation for an individual worker using his/her own hearing protector as typically worn. 

In addition, please note that investigation of engineering noise controls is advisable when time-weighted averages exceed 90 dBA TWA. Different calculations should be used when considering whether workplace engineering noise controls are to be implemented. Contact CavCom for additional information.

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* target protected exposure level = 85 dBA TWA