helikajarõhu
Helikajarõhu (Estonian for sound pressure) is the instantaneous pressure variation in air caused by a propagating sound wave. It represents the deviation of the local air pressure from ambient atmospheric pressure and is proportional to the amplitude of the acoustic wave. The concept is central to describing the strength and perception of sound.
Measurement and units: Helikajarõhu is measured in pascals (Pa). The commonly used quantity is the sound pressure
Relation to intensity and distance: The time-averaged acoustic intensity I relates to p_rms by I = p_rms^2
Applications: Helikajarõhu is used in architectural acoustics, noise control, audio engineering, occupational safety, and environmental noise
See also: acoustics, decibel, sound pressure level, impedance.