The EPA Sound Exposure Level - Ls - describes the noise from a variable source.
The Environmental Protection Agency - EPA - has adopted a system of four "sound descriptors"
- A-weighted sound level
- Sound Exposure Level - Ls
- Equivalent Sound Level - Leq
- Day-Night Sound Level - Ldn
to summarize how sound is heard and measured and to determine the impact of noise on health and welfare.
Sound Exposure Level - Ls
The Sound Exposure Level - Ls - measures the sound change from moment to moment with variable sound. The maximum sound level and the length of time with the sound level greater than certain sound pressure levels are measured.
By accumulating intensity and exposure duration the total sound energy can be measured.
Sound Exposure Level - Ls - can be used to describe noise from moving sources such as airplanes, trains, trucks, etc.