Well, that was certainly an unexpected turn of events!
"I took out the Shark-Fin Headphones, but Peeves started causing trouble and smashed them. Snape confiscated them and said he would find someone to repair them!"
"I took out a brooch, but my hand slipped when I handed it to Professor McGonagall, and it broke in two. There was residual magic on it, since it was a magical brooch that lit up and played music. Besides, wearing a brooch to a party was perfectly reasonable."
"I took out... a Chocolate Frog toy. Professor Binns's cloudy gray eyes told me he had seen right through my trick, but I had to grit my teeth and keep acting. While demonstrating its wonderful magic, I slapped the Chocolate Frog too hard and smashed it!"
Smashed it... smashed...
Right. That was very Ron!
"When Professor Snape, Professor McGonagall, and Professor Flitwick took the broken headphones, brooch, and Chocolate Frog to the Headmaster's Office, they were probably angry enough to burn down the entire Castle!" Harry said dejectedly.
"Without the Shark-Fin Headphones, I can't hear that strange voice anymore. Harry, the next time you hear it, don't go off on your own. Otherwise, Argus Filch won't be the only one who gets the wrong idea about you!"
"All right!"
Meanwhile, in the Headmaster's Office, Dumbledore, Snape, McGonagall, Flitwick, and Binns stood around the desk, exchanging looks!
"Clearly, Hermione, Ron, and Luo Bin played a little trick on us. These are just ordinary little toys!" Professor McGonagall said, her hat trembling.
"Not entirely. The magic on the brooch and the Chocolate Frog is quite commonplace, but forgive my limited knowledge: I cannot unravel the mysteries of the residual magic on these black headphones. I think I must write to Nicolas Flamel. He knows experts in this field!"