soundpressure
Sound pressure is the local deviation from ambient atmospheric pressure caused by a sound wave. It is a scalar acoustic quantity measured in pascals (Pa) and varies in time and space as the wave propagates. Instantaneous sound pressure describes the momentary pressure fluctuation, while root mean square (RMS) values are used for steady-state level comparisons.
Sound pressure is commonly expressed logarithmically as sound pressure level (SPL) in decibels: SPL = 20 log10(p/p0),
Physically, sound pressure relates to particle velocity and acoustic intensity; for a plane progressive wave in
Sound pressure is a fundamental parameter in acoustics, audio engineering, environmental noise assessment, and hearing safety.