IDEA:
Aang was a master ventriloquist, and he used it to screw with everyone because he is a ~little shit~
As an airbender, it would be child’s play to redirect his voice.
The Gaang didn’t find out about this secret talent of his until Sokka gave the poor guy a swig of cactus juice and suddenly even the clothes they were wearing sounded like they were talking in slurred words.
Katara pulls Aang aside and warns (threatens) him in detail what would happen to him if he ever tried that nonsense in the bedroom with her. (He does it anyway, and the hilarity that it caused was so worth it, even if he barely got two dozen yards away before she froze him solid and dragged him, giggling, back from whence he tried to escape.)
Toph is both amused and unamused by all of this because she loves everyone’s reactions, but she gets miffed (and quite startled) when she hears something from where her seismic sense does not see it. (Aang makes Toph off-limits, and she is grateful for it though she doesn’t show it to keep up her cool—Aang knows this.)
Messing with Sokka is the best because he will try to verbally reason-away how it could possibly be that his sealjerky was talking because there had to be a scientific explanation.
Zuko is immune because he had fucking dragons talking to him in his nightmares, so he could not give any less of a damn.
Tune in next time when the ‘Aang is a little shit’ chronicles continue...
(I almost want to add that Aang could send little messages in airballs like how Spongebob and Patrick did with the bubbles in that one episode, but I think that might be too much of a stretch...though I still adore the idea. Just imagine him bugging Zuko as he tries to get the fuddy-duddy Firelord to take a day off lmao.)