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The daily noise exposure levels measured can be also presented as the % of the daily limit, and such representation of the result is called a noise dose. LEX daily noise exposure level – in the case of occupational noise, the LEQ is measured in 8 hours of a working day and such result is referred to as the daily noise exposure level (LEX).LAE is used in environmental noise measurements (vehicle passages: cars, trains, aircraft) For this reason, LAE is often defined as LAeq normalized to 1s. The LAE is equal to the sum of LAeq over a time intervaland 10 logarithms of the ratio of the time interval length to 1s reference time. Sound exposure level (LAE) is the logarithm to the base 10 of the ratio of A-weighted sound exposure over time intervals (T) to the reference value of sound exposure.Time-weighted sound level is usually used for noise surveys and acoustic background measurements. For time-weighted sound levels measurements symbols are LAF, LAS, LCF, and weightings A or C and time weightings Fast (F) and Slow (S). Time-weighted sound level (LAF or LAS) is the logarithm to the base 10 of the ratio of the running time average of the time-weighted square of a frequency-weighted sound-pressure signal to the square of the reference value 20 micro Pascals.The SPL measures decibels with an A-weighting scale (dBA) to measure the human ear’s response to different sound pressure levels. Sound pressure level (Lp), is the logarithm to the base 10 of the ratio of the time-mean-square of sound pressure to the square of the reference value 20 micro Pascals.Peak sound level (Lpeak) is the logarithms to the base 10 of the ratio of the squared greatest sound pressure (positive or negative) during a time interval to the reference value of 20 micro Pascal.
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The LEQ is the most commonly used sound measurement quantity in acoustics because it is directly to sound energy. Time-averaged sound level or equivalent continuous sound level (LAeq) is the logarithm to the base 10 of the ratio of the frequency-weighted sound pressure over a time interval to the squared reference value of 20 micro Pascals.In the field of acoustics, the IEC 61672-1 standard defines sound measurement indicators to quantify and rate sounds in decibels: Sound Measurements Quantities rate sounds in a way that aligns with how the human ear perceives sound, which can be especially useful in contexts like noise control, sound design, and health and safety assessments.