Attenuates sounds without complete muffling. Party plugs are probably not enough to save your hearing at a loud concert, but they definitely have an effect on screeching highs. Better than nothing, and not as extreme as foam plugs.
But maybe I have large or deep ear canals because inserting with even the slightest pressure meant I had to fish these out of my ears with tweezers. Only pair of plugs I've ever had that issue with. Wish they had a longer tab or string to pull them out with. At least they're pretty "invisible" if you don't mind trouble getting them back out.
Another attempt at attenuation for the trash. :(