Other types of modulation have different spectral masks for the same purpose.

Each foot soldier wear different mask depending the one who lead them.

Within two days, they'd have a different mask on their face," says Stephenson.

As his mouth turns up or down, we believe he has pulled different masks on and off.

But I didn't fight and bleed in the rebellion just to see the Families take control again behind a different mask.

Eugene has two different masks to face public and private.

Rand, wearing different masks, until suddenly one of those false faces was no longer a mask, but him.

The performer has ten different masks, and also uses his normal face as a "mask" in the performance.

He picked up a couple of shopping bags full of them, probably about 30 or 40 different masks.

"Can these people rise from one social rank to another," she asked, "merely by wearing a different mask?"