IRSST - Institut de recherche Robert-Sauvé en santé et en sécurité du travail

The effect of wearing hearing protectors and safety helmets on the perception and sound localization of reverse alarms


The use of reverse alarms is obligatory for most heavy vehicles. Despite this, there are still many accidents caused by vehicles moving in reverse. Previous studies have demonstrated the limits of the effectiveness of conventional alarms (beep… beep) compared to broadband alarms (sh… sh) in alerting workers to the presence of heavy vehicles reversing, especially in terms of correctly localizing the sound source.

Given that workers are often obliged to wear hearing protectors and safety helmets in environments where reverse alarms are in use, this study will analyze audibility (detection threshold, reaction threshold and evacuation time) and ability to localize the two main types of reverse alarm.

The results will help enhance workplace awareness of the importance of understanding the impact of wearing hearing protection and to consider alternatives in environments where reverse alarms are frequently used. These could include changing traffic routes when vehicles are backing up in close vicinity to workers.