Evaluation of Occupational Noise Exposure – Advantages and Disadvantages of Noise Dosimetry versus Sampling Using a Sound Level Meter

There are two methods for evaluating noise exposure in the workplace: dosimetry using a Personal Sound Exposure Meter (PSEM) and sampling using a sound level meter (SLM). This paper discusses the advantages and disadvantages of both methods in the context of the fundamental objectives of an occupational noise survey, i.e. identification of exposed workers, determination of exposure magnitude, and identification of the noise sources, processes and activities that contribute to exposure. Exposure evaluation using a sound level meter is quick and reliable when noise levels are relatively low and when exposure varies little as a function of time. When noise levels are very high, however, even very small changes in assumed exposure duration can have a significant effect on the calculated exposure. On the other hand, dosimetry avoids having to estimate exposure durations but can take much longer to assess an entire workforce. These aspects, as well as equipment and measurement considerations are discussed and it is concluded that a well designed measurement strategy is likely to incorporate both methods.