Noise Dosimetry and Noise Index Calculations

The individual noise exposure for constant sound level conditions, and hence the noise injury risk, can be estimated by conventional measurement of sound intensity, frequency and duration of exposure. The durations of different intensity components of intermittent noise of known periodicity can be easily estimated from noise index calculations such as Swedish Standard SEN 590111. For intermittent exposure where the noise source varies in an uncontrolled manner, or when the exposed person moves between different noise zones, the total exposure can be recorded by the personal noise dosimeter which instantaneously integrates sound pressure and duration of exposure.28 noise dosimeters type SRA 71 have been exposed to 100 dB “white noise” under standardized conditions. The results show good agreement between dosimeters and for the same dosimeter on different occasions. A nomogram has been prepared for converting the total noise dose to an equivalent sound level in dB(A).The Swedish norms are based on tables wh...