Sound - Leq - Equivalent Level

Calculate equivalent sound level (Leq) which quantifies the noise environment as a single value. The EPA-adopted system descriptor represents varying sound sources over a given time period as a single number, correlating with effects of noise on people.

Calculator

Inputs

Results

Time 1 - Total Seconds-- s
Time 2 - Total Seconds-- s
Total Time-- s
Leq Total - Equivalent Sound Level-- dB
ParameterValueUnit
Leq 1inputs.leq1dB
Time 1inputs.time1_hours + ' h, ' + inputs.time1_minutes + ' min, ' + inputs.time1_seconds + ' s'
Leq 2inputs.leq2dB
Time 2inputs.time2_hours + ' h, ' + inputs.time2_minutes + ' min, ' + inputs.time2_seconds + ' s'
Leq Total10 * Math.log10((1 / ((inputs.time1_hours * 3600 + inputs.time1_minutes * 60 + inputs.time1_seconds) + (inputs.time2_hours * 3600 + inputs.time2_minutes * 60 + inputs.time2_seconds))) * ((inputs.time1_hours * 3600 + inputs.time1_minutes * 60 + inputs.time1_seconds) * Math.pow(10, inputs.leq1 / 10) + (inputs.time2_hours * 3600 + inputs.time2_minutes * 60 + inputs.time2_seconds) * Math.pow(10, inputs.leq2 / 10)))dB

Equivalent Sound Level - Leq

Equivalent Sound Level quantifies the noise environment to a single value of sound level for any desired duration. It represents a varying sound source over a given time as a single number.

Formula

Equivalent sound levels can be combined as:

Leq_total = 10 log(1 / (t1 + t2 ... tn) (t1 10^(Leq_1/10) + t2 10^(Leq_2/10) + ... + tn 10^(Leq_n/10)))

Where:

  • Leq_total = total equivalent sound level (dB)
  • t1, t2, ... tn = time periods (s)
  • Leq_1, Leq_2, ... Leq_n = equivalent sound levels (dB)

Example

A machine generates sound at 60 dB for 0.5 hours (idling) and 74 dB for 0.5 hours (working).

The combined equivalent sound level is calculated as:

Leq_total = 10 log((1 / 1 hour) (0.5 × 10^(60/10) + 0.5 × 10^(74/10))) = 71.2 dB