CNEL Community Noise Equivalent Calculator

DeclaredCaliforniaCNEL12day3evening9night hourwindows,+5/+10dBpenalties,allactualLeqwindowscomplete,noconflateLden16/8 convention. Actual matched calibration,units,edition,geometry/measurement and model applicability independently established;not hearing/structural safety,compliance or universal perceptual prediction.

Description

Community Noise Equivalent Level combines day, evening and night energy averages with time-of-day penalties.

Community Noise Equivalent Level combines day, evening and night energy averages with time-of-day penalties.^[1]

This calculator uses the declared 12-hour day, 3-hour evening and 9-hour night convention with +5 and +10 dB penalties.

When to use CNEL Community Noise Equivalent Calculator

Use this tool to apply the stated cnel community noise equivalent calculator operation with an explicit input and unit basis.

How to use CNEL Community Noise Equivalent Calculator and how it works

Establish the measurement basis and units described above.
Enter actualDayLeqDb, actualEveningLeqDb, actualNightLeqDb and run the tool.
Read result.cnelDb using the output meanings below.
If input is rejected, correct the stated type, range, ordering or alignment issue and rerun; review successful results under the declared convention.

Input field	Meaning	Value type	Requirement
actualDayLeqDb	Day Leq Db. Units, ordering and applicable branch are specified in the algorithm.	number	required; finite; further conditions in the algorithm
actualEveningLeqDb	Evening Leq Db. Units, ordering and applicable branch are specified in the algorithm.	number	required; finite; further conditions in the algorithm
actualNightLeqDb	Night Leq Db. Units, ordering and applicable branch are specified in the algorithm.	number	required; finite; further conditions in the algorithm

Use the supplied complete-window Leq values on a matched weighting and measurement basis. Combine energy terms with weights 12,3,9 after adding evening and night penalties, divide by 24 and convert back to dB; the helper subtracts the maximum level before exponentiation for stability.

CNEL = 10log10((12×10^(Ld/10)+3×10^((Le+5)/10)+9×10^((Ln+10)/10))/24)

Apply the declared units, ordering and branch conditions.

Output field	Meaning	Value type
result	Object containing the declared output fields.	object
result.cnelDb	Declared 24-hour penalty-weighted energy average in dB on the supplied weighting basis.	number

json

{
  "input": {
    "actualDayLeqDb": 60,
    "actualEveningLeqDb": 60,
    "actualNightLeqDb": 60
  },
  "output": {
    "result": {
      "cnelDb": 66.67012336869195
    }
  }
}

Limitations and assumptions

The output applies the declared operation to the values you supply. Establish the measurement basis, units, coefficients and any caller-selected rules before interpreting it. The tool does not independently collect or verify observations or decide whether a model or reference applies.

Supply explicit required fields with the documented types and dense aligned arrays. Unknown fields, wrong types and nonfinite numbers are rejected. Branch-specific constraints are explained above. A returned boolean, signed difference or tied result follows the stated convention; an input error instead means the required input contract was not satisfied. Very large inputs or outputs may be rejected by shared resource limits.

Alternative or Complementary methods

For a related operation, use Traffic Noise L10 Estimate Calculator. Traffic-noise L10 describes a level exceeded for a specified portion of a measurement period or predicted under a qualified model.

For a related operation, use Percentile Statistical LN Level Calculator. An Ln noise level is exceeded for n percent of the observation time.

References

CNEL Community Noise Equivalent Calculator — tool.io

Similar or alternative tools

Traffic Noise L10 Estimate Calculator
Traffic-noise L10 describes a level exceeded for a specified portion of a measurement period or predicted under a qualified model.
Percentile Statistical LN Level Calculator
An Ln noise level is exceeded for n percent of the observation time.