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Calcimator

Noise Dose Calculator

Calculate OSHA noise dose percentage and TWA from segmented dBA exposures using the 5-dB exchange rate formula.

Inputs

Results

Noise dose (%)

81.3%

8-hr TWA (dBA)88.5
Total exposure hours8
Exceeds action level?1
Exceeds PEL?0
Annual dose-days20,313
How to Use This Calculator
  1. Enter Segment 1 level (dBA), Segment 1 duration (hrs), and Segment 2 level (dBA).
  2. Set Segment 2 duration (hrs), Segment 3 level (dBA), and Segment 3 duration (hrs).
  3. Adjust Segment 4 level (dBA), Segment 4 duration (hrs) as needed.
  4. Review the Noise dose (%) result.
  5. Use 8-hr TWA (dBA) and Total exposure hours to inform your decision.

How the result changes with Segment 1 level (dBA)

Segment 1 level (dBA)Noise dose (%)
1531.3%
5331.3%
98107%
13512,831.3%

What each input means

Segment 1 level (dBA)
Sound level in decibels (A-weighted) during segment 1.
Segment 1 duration (hrs)
Hours of exposure at segment 1 level.
Segment 2 level (dBA)
Sound level during segment 2.
Segment 2 duration (hrs)
Hours of exposure at segment 2 level.
Segment 3 level (dBA)
Sound level during segment 3.
Segment 3 duration (hrs)
Hours of exposure at segment 3 level.
Segment 4 level (dBA)
Sound level during segment 4 (leave 0 if unused).
Segment 4 duration (hrs)
Hours of exposure at segment 4 level.

What each result means

Noise dose (%)
Total noise dose as percentage. 100% = OSHA PEL (90 dBA TWA).
8-hr TWA (dBA)
Time-Weighted Average sound level over an 8-hour shift.
Total exposure hours
Sum of all segment durations.
Exceeds action level?
1 if dose ≥ 50% (TWA ≥ 85 dBA), 0 otherwise.
Exceeds PEL?
1 if dose ≥ 100% (TWA ≥ 90 dBA), 0 otherwise.
Annual dose-days
Projected cumulative dose over 250 working days.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Segment 1 level (dBA) = 95, Segment 1 duration (hrs) = 2, Segment 2 level (dBA) = 85, Segment 2 duration (hrs) = 4 = 8 input(s) provided
  2. Calculate Noise dose
    Noise dose = doseFraction * 100
    81.3 = 81.3
  3. Calculate 8-hr TWA
    88.5 = 88.5
  4. Calculate Total exposure hours
    Total exposure hours
    8 = 8

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