Auditory localisation of a fork-lift truck reversing alarm with hearing protectors

Abstract

Noise exposure in occupational settings has been a source of several studies and research, but the phenomenon of noise also occupies some prominence in the concerns of society, since it affects a significant proportion of the population and presents a large diversity in what concerns the sources of emissions. Auditory perception is one of the most important senses, other than vision, used to access the knowledge of space and thus is also useful to recognise the distance from the acoustical stimulus and its spatial location. Noise exposure is not only a cause of hearing loss, but also a source of verbal communication degradation, decreasing the workplace safety and workers’ performance1.As a consequence of this, the use of hearing protective equipment is increasing.However, the selection process for hearing protection devices (HPDs) is not always done properly. Many workers complain that the use of hearing protective equipment does not allow them to communicate, or to hear and locate important warning sounds at the workplace2-3. It is also agreed that, in addition to the characteristics of attenuation of hearing protection equipment, there are other important factors that may affect the individual ability to perceive auditory signals. These factors include the comfort afforded by the devices, the attention (or lack thereof) of the listener, the characteristics of the warning signals and the users’ hearing loss4. This work aims to analyse the influence of the use of individual hearing protection in the perception of space localisation and distance identification of a backup alarm signal used in industrial forklift trucks