**Noise Dose is the total Sound Exposure normalized to an 8-hour working day**

The **Noise Dose** criteria in the UK is currently 85dBA and if anyone is exposed to an time weighted average noise level of 85 dBA during an 8-hour period their *Noise Dose = 100%*.

The British and ISO Standards are based on the 3 dB exchange rate, which means noise levels of 88 dBA have twice as much energy as levels of 85 dBA. It follows that if *85 dBA = 100% Noise Dose*, then *88 dBA = 200% Noise Dose* and therefore the maximum exposure time is restricted to 4 hours per shift - ergo twice the level means half the time

The 8 hour average level is known as the Daily Personal Noise Exposure LEP,d or LEX,8h.

The **Noise Dose** (in physical units) for the whole measurement duration of sound exposure is known as E (Pa².h)

For a given period of time, an increase of 10 dB(A) in sound pressure level corresponds to a tenfold increase in the *Noise Dose*.

1 Pa²·h = 100% Noise Dose = 85 LAeq(8 h) = 85 dBA for 8 hours.

0.1 Pa² = 74.9 LAeq,8 h

0.2 Pa² = 78.0 LAeq,8 h

0.5 Pa² = 81.9 LAeq,8 h

1 Pa² = 84.9 LAeq,8 h = 100% Noise Dose

2 Pa² = 88.0 LAeq,8 h

5 Pa² = 91.9 LAeq,8 h

10 Pa² = 94.8 LAeq,8 h

0.2 Pa² = 78.0 LAeq,8 h

0.5 Pa² = 81.9 LAeq,8 h

1 Pa² = 84.9 LAeq,8 h = 100% Noise Dose

2 Pa² = 88.0 LAeq,8 h

5 Pa² = 91.9 LAeq,8 h

10 Pa² = 94.8 LAeq,8 h

The Noise Dose examples above assume the UK and EU default criterion time of 8 hours and exchange rate of Q = 3

See also : Projected Dose and Threshold Level**% Noise Dose** is the noise exposure expressed as a percentage (%) of an 8-hour working day. In the UK the 100% level is 85 dBA using the
3 dB exchange rate. **% Noise Dose** varies according to National Standards.

**Noise Damage Risk Criteria** : the recommended maximum noise levels for given exposure periods.

See also :
Exposure Action Value •
Exposure Limit Value

**Noise Dose %** : the amount of noise expressed as a percentage of the normal allowable daily collected during a measurement on a worker with a noise dosimeter. **Noise Dose %** varies according to National Standards

**Noise Dose Badge** : small device worn by operator to store fluctuating noise levels during working day. Similar to a Dosimeter.

**Noise Dose per Hour : DOHR** shows the dose exposure over each hour.

**Noise Dose Threshold Level** : some regulations specify that for the measurement of noise at work, the sound levels below a certain limit (the threshold) should be disregarded. **A Noise Dose Meter** therefore only sums up the contributions from the levels above the threshold and uses these values to calculate the Noise Dose parameters.

**Noise Dosimeter** : a pocket sized instrument designed to be worn during all or part of the day as a **personal monitor** in order to check an operator's personal exposure to workplace noise.

Also known as a **Noise Dosemeter** and a Sound Exposure Meter

**Noise Exposure Time** the time a person is exposed to noise during a workday - used for calculation of LEP,d - Daily Personal Noise Exposure.

**Estimated Noise Dose** : the exposure received if the measured level had existed for the specified criterion time.

**Projected Noise Dose : NProjDose ** uses the current *Noise Dose* value, logged during the present measurement, to be projected forward to give the predicted 8 hour period, assuming the sound levels for the remaining time stays the same.

See also : Sound Exposure • PSEM Personal Sound Exposure Meter