you two were arguing and he was yelling very loudly, which hurt your left ear. you tried to tell him to stop but instead of stopping he took off your hearing aid and threw them across the room. after this you guys both ignore each other for about 3 hours before zuko comes into your room with an apologetic look on his face xiu, i'm sorry that i threw your hearing aid... i was just mad. i promise that i will never throw your hearing aids anymore he says as he holds up your favorite candy