What is the maximum NRR value some earplugs exceed?

• A. 10 dB
• B. 20 dB
• C. 30 dB
• D. 40 dB

Answer: (C)

NRR stands for Noise Reduction Rating, a lab-based decibel value that estimates how much sound a hearing protection device can reduce at the ear when it’s worn properly. For earplugs, that rating tops out around 30 dB, so the maximum value some earplugs exceed is about 30 dB. In real use, the actual protection is often a bit less because fit and movement affect the seal. Values like 10 or 20 dB are below that ceiling, while 40 dB is higher than what most standard earplugs achieve.