Why can't a broken cannon make a sound?

The folding method is wrong or the paper is not thick enough.

No sound can be made when folded. Maybe you folded it wrong, or the paper was not thick enough. The folding method of origami gun is to prepare a rectangular piece of paper with a certain thickness, fold it in half and open it, leaving a midline crease. Fold the four corners of the rectangle in half to the center line, fold it up and down, and then fold it left and right. Fold an angle up along the middle crease, and the hem is a diagonal. Repeat the above operation on the other side to complete the folding.

When we grab the paper gun and throw it down hard, the folded paper will bounce off. Cause the air to vibrate suddenly and send out powerful sound waves. Sound waves rush through the air and reach your ears, and you hear the noise.