The harder we strike, blow, pluck or scrape soundmakers, including musical instruments, the louder the sound it makes

young girl playing with musical instruments at a playcentre.

The size (amplitude) of the vibration determines the volume of the sound. The amplitude of the vibration carries the energy. A big vibration causes large sound waves that transmit a lot of energy. The resulting volume of sound is loud – for example, hitting a table with a ruler.

A small vibration causes small sound waves that transmit less energy. The resulting volume of sound is soft – for example, tapping a table with a ruler.