please try not to use wikipedia as a source, but all answers are appreciated
They sell sound absorbing panels at some musical stores and hard ware stores. They are made to absorb sound in recording studios and such. You could probably find some at a soundworld or another retailer. I'm guessing that there cold be a cheap way to rig somthing up but idk. If this is for a science question or somthing then I'm sorry I couldn't be more specific.
porous materials like matted or spun fibers, panel absorbers having an impervious surface mounted over an airspace, but porous absorbers are the most commonly used sound absorbing materials like carpet, draperies, plaster...(gotta be aerated), fibrous mineral wool and glass fiber, felted or cast porous ceiling tilespray-applied cellulose, and open-cell foam....but these usually convert the sound energy to heat energy. they all have to be thick coz if its too thin on a hard surface underneath then it wont do much at all...you can also, for panel absorbers, do glazing and other large surfaces capable of resonating when thers sound but thats getting into too much detail... if yur not wanting to do any of that - flat egg cartons!......just plaster them all over the wall making sure there's no gaps or spaces and it works perfectly!!!
