Efficiency of hearing protectors : what is the value of the personal and in the field methods of assessment today proposed?

The assessment or the measurement of the personal and in the field attenuation of hearing protective device (HPD) is a current challenge that must be addressed to comply with the regulation. This is why some manufacturers now offer HPD attenuation measurement systems, tailored from standard reference methods. Occupational Health actors might be tempted to believe that these measurement systems are an ideal solution to answer to the question: what is the residual noise into the ear of an employee exposed to noise and wearing an HPD? INRS decided to test four of these systems in order to show their limitations. Three are dedicated to earplugs and the fourth to headsets. 20 persons were used to test 8 HPD with these systems and to compare with reference methods. The results show often slightly larger differences with commercial systems, compared to reference methods, but three of the four systems are acceptable. The occupational physician can use one of the three methods to answer the question of the actual attenuation of hearing protectors. He will be particularly interested to consider them as an evidence of a good adaptation of the HPD to the employee concerned and also as a teaching aid and motivation to wear the protector.