What would you use to make an ear defender?

if i made ear defenders i would :

Use foam because - it will absorb the sound

Use rubber because - it has a lot of air bubbles in it. Sound takes a long time to travel through gases like air . Also some of the sound may reflect off the rubber. airpoo

Vacuums, because sound travels best through air and there would be no air to travel through.

And use cotton wool. : )