Mouth of Sauron's helmet insciptions

[Damrod]

Heard this on a commentary track

There's incantations of Black Speech etched into the metal around [The Mouth's] mouth and the idea being that it enhances the evil that he speaks.

That's Richard Taylor, one of the big bosses at WETA, I think. Ninja91's theory is much more interesting to me, but I'm still trying to find out what those runes actually say.