I made one myself. I ain't too good at explaining but i shall try XD
Take safety headphones, and take one of the muffs off. Take a knitting needle and attach a piece of black/grey foam to the end as microphone. Attach the knitting needle with the free end to the muff that is still attached to the headband, and bend the knitting needle so it is in front of your mouth.
I was lucky i could attach the needle easily, so i think you'd have to figure out yourself how to get it on easily.
I hope it helped XD
My props: tumblr
Currently in progress
-lady -DMC 3
-Alphonse Elric's full armour -FMA