The noise dosimeter for measuring personal noise exposure

Abstract

A pilot study of personal noise exposure measurements with the use of noise dosimeters is presented. The value of objective individual recordings regarding the intensity and the exposure time is emphasized. Unexpected daily variations were detected also among employees assumed to work in fixed noise—level environments. Objective measurements of intensity and exposure time completed by a calculation of the frequency parameter seem more adequate than the previously used objective measurements of intensity and frequency completed by a rough estimation of the time parameter. The dosimeters have also discovered great variations in the individual noise panorama following a change from night to day shift or seasonal production fluctuations. Repair and inspection of factory machines involve also great individual increases in noise exposure. With the dosimeters it was also possible to distinguish between three different groups of employees in the factory with regard to their exposure to noise. So far it seems practical to allow a noise exposure above the linear 85 dB level of 0.5 decibel hour per working hour (dBh/h), whereas an amount of noise exceeding 1.0 dBh/h is not tolerable unless adequate noise protectors are used. Further investigations are necessary before definite prescriptions for the practical utilization of the noise dosimeters can be recommended.