Sound intensity is the amount of sound energy that passes through a given area per unit of time. It is also called [[sound pressure level (SPL)]] and is typically measured in units of watts per square meter (W/m²) or [[deciBel|deciBels]] (dB). Sound intensity is related to the amplitude of the sound wave, which is the measure of the air pressure fluctuations caused by the sound wave. The higher the amplitude, the higher the sound intensity, and therefore, the louder the sound. The sound intensity is measured with a sound level meter. ![[sound-level-meter.png]] In this recording, every new pulse has an intensity of -3dB than the previous one: ![[3db-steps.wav]]