The stupid voice is laughable and lovable at the same time. Maybe it's because of the childlike innocence that comes with it, but whatever the reason, it's hard not to fall in love with the character using it.
The stupid voice highlights a dim-witted character, who shows a degree of obliviousness to everything and lacks common sense. The lack of intelligence is usually exaggerated to make the audience laugh.
It is mainly used in comedy skits and funny commercials but could also be useful for dumb radio and audiobook characters and book narrations. Although the stupid voice was a feature in cartoons and animated films in the old days, it is now widely used in mainstream TV shows and movies to add comedic breaks and engage the audience.
No, I'm not crying, my eyeballs are sweating.' The stupid voice showcases the character’s lack of understanding of basic things and can either be used to shrug off questions or explain something common and well known in a sarcastic way. Context is everything for this voice. The stupidity showcased is dependent on the setting, the script, and the set-up. One wrong move and the character will simply come off as dumb and not funny.
Good use of the stupid voice gets the audience thinking, “It doesn’t even make sense, but why is it so funny?” The voice only amplifies the stupidity in whatever the character says, so if the voice is used on a statement that is somewhat intelligent, it will not come off right.