Paragraph 3.2 Equivalent continuous sound pressure level LAeq:(t1, t2)

The equivalent continuous sound pressure level L_Aeq:(t₁, t₂) is obtained by applying the A-weighting as defined in IEC publication 651, first edition, 1979 to the equivalent continuous sound pressure level L_eq:(t₁, t₂) defined below. This weighting is obtained inter alia by using the A-weighting filter in the measuring system.

The equivalent continuous sound pressure level for a limited period between intervals t₁ and t₂, L_eq:(t₁, t₂), expressed in decibels, of a noise at a given point is defined by:

where:

• p(t) is the instantaneous value of the sound pressure at this point, expressed in Pa;

• p₀ is the reference sound pressure, equivalent to 20 μPa;

• L_p(t) is the sound pressure level at a given time at that point, expressed in dB;

• t₁ and t₂ are the points indicating respectively the beginning and end of the reference period determining the L_eq

• t₁ − t₂ is the measurement interval.