* Balloon
Blow a balloon hard and tap it lightly near your ears. Hear the sound and compare the lightness of the action with the sound produced.
As the air molecules get closer and well packed inside the balloon they turn into a better conductor of sound than ordinary air and contribute to producing louder sounds.
* Even light tapping produces a loud sound to the ear. * When air is blown in it forces air molecules closer together that produces a loud sound.