The volume of a sound depends on the ___ of the sound waves?

The volume of a sound depends on the amplitude of the sound waves. The amplitude of a sound wave determines its volume (a larger amplitude means a louder sound, a smaller amplitude means a softer sound). The vibration of a source sets the amplitude of a wave. More energetic vibration corresponds to a larger amplitude. The molecules move more vigorously.

The volume of a sound is also determined by the sensitivity of the ear (human ear is more sensitive to some frequencies than to others). It depends on both the amplitude of a sound wave and whether its frequency lies in a region where the ear is more/less sensitive.