The influence of hearing protectors on the auditory perception of warning signals in the railroad environment.

In some railway environments, high noise exposure levels require hearing protector devices (HPDs) to be worn by the workers. However, for specific activities, auditory warning signals are used to alert workers that there is a potentially dangerous situation. Wearing HPDs therefore requires two different issues to be achieved: to protect the worker’s hearing and to guarantee their safety by ensuring that auditory warning signals are audible. In order to be able to study the influence of wearing HPDs in many acoustical situations and for many SNCF workers, specific psychoacoustic laboratory tests and analysis methods were developed by CNRS, INRS and the SNCF prevention services. Three occupations were considered: train drivers, track-laying workers and station agents.
Methods and results are presented as well as their limits compared to real work conditions and to the auditory status of the workers wearing HPDs.