Alicia Witt's voice as Alia in DUNE

A friend wondered if Alicia Witt’s “Alia speaking voice” in DUNE was dubbed in by another actress, electronically enhanced (similar to The Weirding vocal effect), or purely natural. Googling yielded no answers. I just wrote her website to ask but I beseech the collective Doper intelligence for a speedier reply. Thanks!

Assuming this is legitimately Witt answering, yes, it was dubbed.

She was in fact dubbed by Nipsey Russell, who wrote his own dialogue:
“I wish with my grandaddy Harkonnen
I’d played some knick knack paddy whack
Cause then I’d be moved by his moanin’
That my brother’s the Kwizatz Hadderach!
I’ll take that heart plug, bye bye!”*

(No cite available.)

She grew up absolutely loverley, did she not?