REST OF THE WORLD » Choose region



User Segments

Search by function

Technical support


Learn more

PDF library

Contact us

About Us

Peltor Communications Extranet

Go to 3M Website

The concept of equal energy the noise dose

The risk of injury is a combination of the A-weighted sound level and the time spent in it. For example, fifteen minutes at a 100 dB(A) sound level has the same effect as 8 hours at 85 dB(A). This i determined by using the so-called equal energy principle.

Energy equals intensity times time. If the sound level increases by 3 dB, the intensity doubles for example, if you have one machine in a workplace, and place another one in the same facility the noise level will raise by 3 dB. This method is described in the International standard ISO 1999:1990.

1 2 3 4 5 6 7 8 9 10 11 12 13

Magnus Johansson, Peltor AB


  How does sound occur
  The auditory system 
  The outer ear 
  The middle ear
  The inner ear
  Exposure to noise 
  Hearing impairment
  The concept of equal energy
  How to measure noise levels
  Choose right hearing protection
  Do not over attenuate
  Noise regulations