For earplugs most have an NRR of at least ____ dB and some exceed ____ dB.

• A. 10, 15
• B. 20, 30
• C. 25, 40
• D. 15, 25

Answer: (B)

Understanding NRR and typical protection ranges helps explain why earplugs commonly list about 20 dB as a baseline and up to around 30 dB for higher protection. The NRR is a lab-measured number that estimates how much sound the plug can reduce when worn correctly, though real-world protection varies with fit and use. Most everyday earplugs provide about 20 dB of attenuation, and many higher-attenuation models push toward 30 dB. The other ranges don’t match what’s commonly available: 10 or 15 dB would be relatively weak protection, while 25 dB with 40 dB at the top is unusually high for typical consumer plugs. The 20 dB minimum and around 30 dB maximum reflect the common spectrum of earplug products.