Sound level
The sound level is a colloquially shortened term for the level of an acoustic variable, which is usually given in the auxiliary unit of measurement decibel . One of the following sizes can be meant:
- predominantly, it will be the sound pressure level L p as the sound field quantity that describes the sound impact on a specific location ( sound immission ) and depends heavily on the type of environment (e.g. in a room or outdoors, distance to a sound source ), less often
- the sound power level L W , which describes the strength of a sound source ( sound emission ) and does not depend on the type of environment, but on the properties of the sound source.
- the sound intensity level L I , which describes the logarithmic ratio of the sound intensity I 1 in a sound field to the reference value I 0 (DIN 45630) as a sound energy variable .
Like the sound pressure level as a sound field variable, the sound intensity level as a sound energy variable is also dependent on location and environment and also direction-dependent.
In order to interpret a specified “sound level”, it is usually not only necessary to know which of these quantities is meant, but often additional information is required, such as the measurement specification used, the associated frequency or time weighting or the location of a measurement and its properties.