Objects that vibrate with more pressure produce higher amplitude sound. Sound amplitude is a measure of the change in pressure. Sounds with higher amplitude have larger changes in pressure. The more energy put out by the sound source, the greater the amplitude of the sound, and the further the sound will travel.

Amplitude: the amount of pressure generated by the wave.

Try it!

1. Strike the tuning fork gently against the heel of your shoe lightly. Next, strike it against the heel of your shoe with a little more force. Can you hear and feel the difference in vibration?

⚠ CAUTION: Striking the tuning fork with too much force will bend the tines and it won’t vibrate correctly to make sound anymore.