Analysis of the auditory localisation of a forklift backup alarm with hearing protectors

摘要

The use of hearing protectors in industrial environments will only be effective if it does not impair users' hearing, in particular the ability to perform specific auditory tasks, such as signal detection and discrimination and sound spatial localization. The aim of this study was to develop a simple laboratorial procedure to analyse subjects' performance, in terms of auditory localization, by comparing different hearing protection conditions (with 3 types of devices) and the unprotected condition. The developed and applied procedure has consisted in testing each subject with a previously recorded forklift backup sound alarm. The study sample was composed of 20 subjects with no previous hearing losses. Subjects were required to locate the position of the noise stimuli in a grid of 9 possible positions located on their back. The sequence of the tested positions, as well as of the protection condition, was randomly generated. Devices were fit by the experimenters to ensure maximum attenuation. Results were compared in terms of detection errors (deviation from the right position) considering the different types of hearing protectors, as well as the unprotected condition. Results shown that the best users' performance, with protectors, was obtained using the tested earplugs. Moreover, when using passive devices users presented a better test performance than with the tested active device.