Measuring How Loud Sound Is

Sound intensity helps describe how loud a sound source is. It depends on how energetically the source vibrates, because those vibrations make the molecules in the medium vibrate as well.

Intensity is the energy emitted per unit time per unit area. The area must be perpendicular to the direction t...

The loudness of a sound is related to the perception it creates on the human ear. It depends upon how energetically the source of sound is vibrating.

The loudness is described by a physical quantity, the intensity. A source's intensity is defined as the power emitted by the source per unit area perpendicular to the direction of propagatio...