The relationship between amplitude and volume is directly proportional. This means that as the amplitude of a sound wave increases, the volume also increases.

Here's a breakdown:

* Amplitude: This refers to the maximum displacement of particles in a medium from their rest position as a sound wave passes through. It essentially represents the "height" of the wave.

* Volume: This is the perceived loudness of a sound.

When the amplitude of a sound wave is higher:

* More energy is transferred: The particles in the medium vibrate with greater intensity, transferring more energy.

* Greater pressure changes: The variations in pressure caused by the sound wave are more significant.

* More intense vibrations: Our ears detect these more intense vibrations as a louder sound.

In simpler terms: A higher amplitude means the sound wave is "stronger" and carries more energy, resulting in a louder sound.