The noise climate at the operator station of construction machines: comparison between naive and experienced subjects

A research project aimed at improving the noise climate at the operator station of construction machines is still in progress. One of its topics includes the subjective evaluation of the modifications induced by an active noise control system. In this respect, a laboratory simulation of its effects has been performed in order to evaluate its effectiveness prior to its implementation. Subjective listening tests have been carried out to collect ratings with respect to some noise features significant for the operator's safety and comfort. The results of a first investigation involving a jury of naive subjects have been already published. The same investigation has been repeated on a jury of experienced machine operators in order to detect whether the experience on the use of these machines provides additional or more detailed information. The present paper describes the results of this latter experiment and tries to draw inferences from the comparison between the two groups of results.