Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

mobile - visible on handheld devices - alternatively go to www.engineeringtoolbox.com!

Engineering ToolBox > L_s - Sound Exposure Level

Sound Exposure Level - L_s - describes noise from a varied source.

The Environmental Protection Agency - EPA - has adopted a system of four "sound descriptors"

• A-weighted sound level
• Sound Exposure Level - L_s
• Equivalent Sound Level - L_eq
• Day-Night Sound Level - L_dn

to summarize how sound is heard and measured, and to determine the impact of noise on health and welfare.

Sound Exposure Level - L_s

measures the sound's change from moment to moment when the sound varies. This varied duration measurement combines the maximum sound level with the length of time during which the sound level is greater than a certain number of decibels below the maximum level.

By summing the intensity by the exposure duration the total energy of the sound can be measured.

Sound Exposure Level - L_s - can be used to describe noise from a moving sources such as airplanes, trains, trucks, etc.