Power and Intensity

Waves can represent a number of time-evolving physical variables (force, velocity, acceleration, etc.).

For sound waves, the physical variable represented by the amplitude of the waveform is pressure.

Related to the sound pressure are

1. the sound power emitted by the source
2. the sound intensity measured some distance from the source.

Sound power:

• a fixed quantity, analogous to the wattage rating of a light bulb.

Sound intensity:

• a quantity influenced by environment surroundings, surfaces, and interference from other sources
• analogous to the brightness of the light in a particular part of the room