Your link is bad.
I'm all for using whatever you find that is the right size & shape. The key to earphones is they are essentially hollow because your ears stick out off the sides of your head (well, not you specifically like Prince Charles or anything, just human ears in general).
So, your prop making needs to incorporate space for your ears.
Also, if you fully cover your ears like headphones do, you will be reducing what you hear, how much depends on the materials used.