Sound intensity level in decibels (dB) is more relevant for how humans perceive sounds than sound intensity (in W/m 2 ), even though sound intensity is the SI unit The energy of a sound wave is also proportional to its amplitude squared

Sound intensity level is not the same as sound intensity—it tells you the level of the sound relative to a reference intensity rather than the actual intensity Sound is a disturbance of matter that is transmitted from its source outward in the form of longitudinal waves

sound — a disturbance of matter that is transmitted from its source outward by longitudinal waves. amplitude — the amount that matter is disrupted during a sound wave, as measured by the difference in height between the crests and troughs of the sound wave. sound intensity level — the level of sound relative to a fixed standard related to human hearing. sound intensity — the power per unit area carried by a sound wave.