biloquist

Probably coined by American novelist Charles Brockden Brown (1771-1810) in Memoirs of Carwin the Biloquist (1805).

biloquist (plural biloquists)

1. (rare) A person having the ability to speak in two different voices, especially as a ventriloquist.
   • 1999, Jack O'Connell, Word Made Flesh‎^[1], →ISBN, page 28:

     Back in Maisel, I was a biloquist. A common street performer. What you would call a ventriloquist.

• biloquial
• biloquism
• biloquium

• Oxford English Dictionary, 2nd ed., 1989.