lydtryk
Lydtryk, or acoustic sound pressure, is the local deviation of ambient atmospheric pressure caused by a propagating sound wave. It is a mechanical pressure fluctuation in the medium (usually air) accompanying sound and is a fundamental quantity in acoustics and audio engineering.
The SI unit of lydtryk is the pascal (Pa). In practice, sound-pressure levels are usually described using
Measurement of lydtryk is typically performed with microphones or hydrophones. The measured p_rms depends on distance
Lydtryk is distinct from sound intensity. Pressure is a local field quantity, while intensity describes the
Applications of lydtryk include noise assessment, architectural and automotive acoustics, and occupational health. Typical reference levels
In Danish usage, lydtryk is the standard term for acoustic pressure, commonly used alongside SPL in technical