You can unlock the option to change the narrator's voice to take the place of anyone of the six playable characters.

Narrator	How to unlock
Amazon's Voice	Beat the game on Normal with the Amazon, then buy it for 1 million gold.
Dwarf's Voice	Beat the game on Normal with the Dwarf, then buy it for 1 million gold.
Elf's Voice	Beat the game on Normal with the Elf, then buy it for 1 million gold.
Fighter's Voice	Beat the game on Normal with the Fighter, then buy it for 1 million gold.
Sorceress's Voice	Beat the game on Normal with the Sorceress, then buy it for 1 million gold.
Wizard's Voice	Beat the game on Normal with the Wizard, then buy it for 1 million gold.