[goda90]

Do you know how these musician's earplugs work? I imagine instead of just blocking vibrating air like regular earplugs, it must be trying to dissipate the sound waves a bit. Is that even possible across the whole range of sound?

[ResidentSleeper]

Materials absorb different parts of the frequency spectrum with varying efficiency. Regular earplugs are made to simply stop as much sound as possible and hence there's a lot of muffle at the top of the spectrum (that's easiest to achieve - cover your ears!). Concert earplugs are more carefully designed to absorb the entire spectrum as uniformly as possible.