Cotton can, sponge should, both of which should be able to isolate sound. I think as long as it is soft, this aspect is definitely a hard indicator, because only in this way will it not hurt the ear, and then the sound insulation material and effect. I think this material must be able to block the penetration of sound. Noise-proof earphone covers are generally made of silicone, which is very soft and comfortable.
Sound insulation effect of earplugs
Silica gel earplugs are soaked in warm water to soften before use. Because the inner wall of the ear canal is curved and soft, if the earplug is too hard, the ear canal will be red and swollen, and if it does not conform to the curved wall of the ear canal, it will also lead to earache and redness. Therefore, it cannot be filled and used for a long time. However, silicone earplugs are easy to clean and can be used repeatedly.
Good hardness, comfortable ear canal, good sound insulation effect and no discomfort after long-term use. Sponge earplugs are made of low-pressure foam material and high-elastic polyester material. The anti-noise earplug has smooth surface, slow rebound, no ear swelling and pain when used, and the sound insulation effect is between 25 dB and 40 dB. This kind of earplug is very suitable for sleeping every night.