Near the end of Banjo-Kazooie, you have to complete a trivia quiz about the game before you can fight the final boss. One of the question categories is sounds, which will either be a sound effect, a piece of music, or a voice clip used by one of the game's many, many, many NPCs. For the voice clip questions, Gruntilda will ask you to select the owner of "this dumb voice". However, because she's more than a bit full of herself, when Grunty herself is the speaker, she says "this cool voice" instead.