Is there an alternative to using personal noise dosimeters for determining risk of hearing loss? Our production facility is based on an assembly line layout, and most of our workers perform only one or two operations in one place all day. The noise levels are steady and it seems that hanging a noise dosimeter on each worker for a full shift is overkill. However, we need to be compliant and we want to get the best exposure data possible. Answered by Rob Brauch, key accounts manager, Larson Davis Inc., Provo, UT.
The benefits of wearing a personal noise dosimeter throughout the entire work shift are most evident in less-structured working environments where there is significant worker mobility and a great deal of unpredictability as to what tasks the worker will perform on a given day.
If your environment is more static and predictable there is an acceptable alternative methodology that can be implemented relatively easily. The noise measurement itself can be performed with an integrating sound level meter instead of a personal dosimeter. This alternative exposure assessment is called the Task-Based Exposure Assessment Method, or T-BEAM.
The T-BEAM concept revolves around creating a detailed breakdown of the various work elements a person typically would perform in the normal execution of his or her duties, and recording a sampled representative noise level for each task. If a worker performs four or five operations each day, and the noise level generated by each operation is known, it is relatively simple to calculate what the actual cumulative noise exposure would be, assuming it is known what the 'time on task' is for that given job description.
Software has been developed that can track the noise exposures of an entire plant's workforce by creating a detailed database of job codes and the tasks associated with each, plus a field for entering the measured noise levels for each task. These noise values, factored by cumulative time per task and then combined, will equal the predicted noise exposure for that job description. Thus, with periodic review of the job tasks and their associated exposure levels – using a sound level meter, which also can have the capability of measuring specific frequency bands - the entire plant's compliance data and hearing conservation program can be managed with maximum accuracy and minimal effort. If a process or task is added or changed, that element's noise level can be measured, added or removed from the composite predicted outcome.