Abstract

The use of back-up alarms is mandatory on most heavy vehicles and remains a widely used means of alerting people working in their vicinity.

Previous studies conducted by the IRSST have shown the limitations of the effectiveness of alarms used in the workplace to minimize risks to workers’ safety. Because of the noise level they generate, workers and people living nearby often regard back-up alarms as a nuisance.

These annoyance and sound perception problems are amplified when workers work in semi-open or completely enclosed environments, such as warehouses, where sound bounces off walls, floors and ceilings, increasing the noise level and creating parasitic reflections that interfere with perception. There are no proven solutions to address all these problems.

The aim of this project is to explore the use of parametric speaker technology for the design of a directional back-up alarm. The technology has existed for years for other applications, but has recently become more accessible through miniaturization and lower costs. This type of speaker produces a focused sound field that can be directed to and concentrated on specific directions or areas. Outside these areas, the sound produced is not at all or only slightly perceptible, which could be a solution to the problems of sound perception for workers and the environmental disturbances it causes.