Whole-day assessments (usually with dosimeter) measure the entire day. While this assessment type can be attractive because you don’t need to know the worker’s schedule, it can make it difficult to identify specific behaviours or tasks that warrant mitigation.
Task-based analysis requires breaking down the workday and dividing it into tasks and then measures with a sound level meter to calculate exposure. This method requires a lot of work to identify and analyze tasks, but it is an excellent tool for finding mitigations for specific tasks. This task may also not be appropriate if workers perform different tasks every day.
Job-based measurement is, in essence, a blending of task-based and whole-day analysis. This method uses typically sound level meters to make random samples of noise exposure measured during the performance of jobs identified during the work analysis. How much measuring is dictated by the standard and based on the size of the work group.
Based on the analysis outcome, employers may be required to take risk mitigation actions. For example, if the exposure is above the action value but below the critical limit of the regulation, employers must institute a hearing conservation program, informing workers about the risk, providing hearing protection with training for proper use, how to actively reduce their noise exposure, and ensuring audiometric monitoring of workers' hearing. If the exposure is above the critical limit of the regulation, employer must take measures to reduce the noise exposure. If it is not possible to do this by changing working pattern, workplace design, noise sources (noise reduced tools and machinery) or using technical means (mufflers, absorbers), workers must wear hearing protection that ensure noise exposure is below the limits.
It is extremely important that the results of any assessments are accurate because mistakes in under or over rating the noise exposure can be costly in terms of expense and worker health. The efforts involved in administering hearing conservation programs and changing the configuration of workplaces can be enormous, as can be the damage if the assessment failed to indicate the risk.