... 3.wearing health, safety, soft silicon / foam anti-noise earplugStudy shows that: the noise would cause people's fatigue, hearing loss, reduce ... anxiety and other negative emotions. More than 100 decibels of noise will have adverse effects on physiological. Fuction: to improve ... sleep, focus, such as the protection of hearing. Noise value (NRR) 29 dB, the smooth surface, with treatment, ...