How can I assess the safety of a deaf worker on a plant using an audiogram. What criteria apply here please. Thank you!

The worker needs a risk assessment by the management to assess their ability to e.g. hear shouted instructions or alerts and alarms when not in the line of sight of the source. Audiograms serve two main purposes: identifying a lapse in control measures (eg PPE) for individuals and worker groups and identifying individuals for whom working control measures are not sufficient. Interventions are hopefully prior to any permanent impairment. Audiograms are not good at predicting what a worker will or will not be able to hear.