How to evaluate the sound isolation performance of an earplug?

In today's noisy world, sometimes we need more than just a quiet environment, sometimes we need earplugs that can help us isolate noise, concentrate, and improve work efficiency.

The main principle of soundproof earplugs is to use the sealing and elasticity of the material to fill the ear canal and block the propagation of sound waves, thereby reducing the sound received by the eardrum. Different sound-isolating earplugs come in different materials, shapes, sizes, and colors, and they block noise to varying degrees.

Generally speaking, the sound isolation effect of sound-isolating earplugs can be measured by Noise Reduction Rating (NRR), which indicates how many decibels of noise can be reduced after wearing earplugs.

Therefore, the higher the NRR, the better the sound insulation effect.

NRR is usually marked on the packaging, and can also be measured with professional instruments or mobile phone software.

BET SLUMBUR earplugs currently have three products: SLEEP, ENJOY and ENJOY Pro. Reach real noise reduction in a specific target frequency. Their noise reduction data are as follows:
BET SLUMBUR SLEEP Earplugs — SNR: 32 dB (NRR: 19.1 dB)
BET SLUMBUR ENJOY Earplugs — SNR: 28 dB (NRR: 16 dB)
BET SLUMBUR ENJOY PRO Earplugs — SNR: 24 dB (NRR: 13 dB)

Common noise environments are 30–40 decibels, and using BET SLUMBUR earplugs can effectively reduce the noise.