Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

This is an AMP page - Open full page! for all features.

• the most efficient way to navigate the Engineering ToolBox!

# Noise - Maximum Daily Dose Level

## Maximum daily noise dose level when exposed to periods with different levels.

When the daily noise exposure consists of periods of different noise levels, the daily dose can be calculated as:

D = ( te1 / td1 + te2 / td2 + ... + ten / tdn ) 100%                              (1)

where

D = daily noise exposure (%)

te = exposure time at a specified noise level (min)

According the National Institute for Occupational Safety - NIOSH - the daily dose level - D - should not equal or exceed 100%.

The daily dose can be converted to an 8-hr Time-Weighted Average -TWA by the formula

TWA = 10 log (D / 100) + 85                               (2)

where

TWA = Time Weighted Average noise level (dB)

Daily noise dose as an 8-hr TWA for different daily noise doses:

Daily Noise Dose
(%)
8-hr TWA
(dB(A))
20 78.0
30 79.8
40 81.0
50 82.0
60 82.8
70 83.5
80 84.0
90 84.5
100 85.0
200 88.0
400 91.0
600 92.8
800 94.0
1,000 95.0
1,500 96.8
2,000 98.0
4,000 101.0
6,000 102.8
8,000 104.0
10,000 105.0
20,000 108.0
40,000 111.0
60,000 112.8
80,000 114.0
100,000 115.0
150,000 116.8
200,000 118.0
400,000 121.0
600,000 122.8
800,000 124.0
1,000,000 125.0
2,000,000 128.0
4,000,000 131.0
6,000,000 132.8
8,000,000 134.0
10,000,000 135.0
20,000,000

138.0

#### Example - Daily Noise Dose Level

During a working day a person is exposed to 100 dB in 5 minutes and 94 dB in 30 minutes.

The maximum noise exposure time for 100 dB is 15 minutes and for 94 dB 60 minutes

The daily dose can be calculated as

D = ((5 min) / (15 min) + (30 min) / (60 min)) 100%

= 83 %

The Time-Weighted Average -TWA can be calculated as

TWA = 10 log (83 / 100) + 85

=  84 dB

## Related Topics

• Acoustics - Room acoustics and acoustic properties, decibel A, B and C, Noise Rating (NR) curves, sound transmission, sound pressure, sound intensity and sound attenuation.

## Search Engineering ToolBox

• the most efficient way to navigate the Engineering ToolBox!

## SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!

## Privacy

We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

## Unit Converters

Temperature

oC
oF

Length

m
km
in
ft
yards
miles
naut miles

Area

m2
km2
in2
ft2
miles2
acres

Volume

m3
liters
in3
ft3
us gal

Weight

kgf
N
lbf

Velocity

m/s
km/h
ft/min
ft/s
mph
knots

Pressure

Pa (N/m2)
bar
mm H2O
kg/cm2
psi
inches H2O

Flow

m3/s
m3/h
US gpm
cfm

6 24

This website use cookies. By continuing to browse you are agreeing to our use of cookies! Learn more