Sound is produced by a school bell through a process called vibration. When the bell is struck by a clapper or hammer, it begins to vibrate back and forth. These vibrations create compressions and rarefactions in the surrounding air. Compressions are areas of high air pressure, while rarefactions are areas of low air pressure. These compressions and rarefactions travel through the air as sound waves, reaching our ears and allowing us to hear the sound of the bell.