Acoustic Glossary


Leq, LAeq : Equivalent Sound Level

Leq is the Sound Pressure Level in dB, equivalent to the total Sound Energy over a given period of time.

Leq is normally based on an Exchange Rate = 3. and the 8 hour Leq level is also known as LEP,d = LEX,8h.

Leq is also referred to as the LAT - time averaged sound pressure level and the Equivalent Sound Level.

Leq is widely used, but not widely understood - click here for a more detailed explanation.
To see a range of Leq Meters click here.

LAeq : it is good practice to include other measurement parameters, such as A-weighting, so other people are aware of how the measurement was made; other examples include:-

LAeq,t : A-weighted equivalent sound pressure level in dB measured over a period of time t.

LCeq,t : C-weighted equivalent sound pressure level in dB measured over a period of time t.

Short Leq : the preferred modern method of storing sound levels and displaying the true time history of noise events and all other sound levels during any specified period of time. The resulting 'time histories', typically measured in 1/8 second intervals may then be used to calculate the 'overall' levels for any sub-period of the overall measurement time.

See also :

Integrating Sound Level Meters
Leq - Equivalent Continuous Sound Level - the more detailed explanation.
SEL - Sound Exposure Level = Leq normalised to 1 second, equivalent to the total Sound Energy.

Related Terms :

CNEL : Community Noise Equivalent Level
LAIeq = A-weighted, Impulse, Leq, Sound Pressure Level.
LAT : Time Averaged Sound Pressure Level
LCeq = C-weighted, Leq, Sound Pressure Level
Lday : Day equivalent level
Lden : Day-evening-night equivalent level
Ldn : Day-night equivalent level
LEX,8h : Daily Exposure Level
LEP,d : Daily Personal Noise Exposure -
LEP,w : Weekly Personal Noise Exposure
Noise Dose
Sound Energy
Sound Exposure
Sound Pressure


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