Michael Bahtiarian is vice president at Noise Control Engineering Inc. in Billerica, Mass., which specializes in industrial and marine noise control. Michael is a Board Certified Acoustic Engineer by the Institute of Noise Control Engineering (INCE). He can be contacted at mikeb@noise-control.com or (978) 670-5339.
Choosing the right hearing protection device (HPD) should be based on two factors: comfort and performance. HPD performance is characterized by a single number rating called the Noise Reduction Rating, or NRR. So just how is this crucial number derived?