Effect of Hearing and Head Protection on the Localization of Tonal and Broadband Reverse Alarms

• Published in: Human factors Vol. 64; no. 7; pp. 1105 - 1120
• Main Authors: Laroche, Chantal, Giguère, Christian, Vaillancourt, Véronique, Marleau, Claudia, Cadieux, Marie-France, Laprise-Girard, Karina, Gula, Emily, Carroll, Véronique, Bibeau, Manuelle, Nélisse, Hugues
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01-11-2022; Human Factors and Ergonomics Society
• Subjects: Accidents, Human Error; Alarms; Background noise; Broadband; Construction accidents & safety; Construction industry; Ear protection; Hearing; Hearing protection; Hearing protectors; Heavy vehicles; Helmets; Localization; Loudspeakers; Occupational safety; Protective equipment; Safety; Safety helmets; Sound; Sound localization; Tablet computers; Workplaces; audition; warning devices; personal protective equipment; workplace safety
• ISSN: 0018-7208; 1547-8181
• DOI: 10.1177/0018720821992223

Objective
This study explored the effects of hearing protection devices (HPDs) and head protection on the ability of normal-hearing individuals to localize reverse alarms in background noise.
Background
Among factors potentially contributing to accidents involving heavy vehicles, reverse alarms can be difficult to localize in space, leading to errors in identifying the source of danger. Previous studies have shown that traditional tonal alarms are more difficult to localize than broadband alarms. In addition, HPDs and safety helmets may further impair localization.
Method
Standing in the middle of an array of eight loudspeakers, participants with and without HPDs (passive and level-dependent) had to identify the loudspeaker emitting a single cycle of the alarm while performing a task on a tablet computer.
Results
The broadband alarm was easier to localize than the tonal alarm. Passive HPDs had a significant impact on sound localization (earmuffs generally more so than earplugs), particularly double hearing protection, and level-dependent HPDs did not fully restore sound localization abilities. The safety helmet had a much lesser impact on performance than HPDs.
Conclusion
Where good sound localization abilities are essential in noisy workplaces, the broadband alarm should be used, double hearing protection should be avoided, and earplug-style passive or level-dependent devices may be a better choice than earmuff-style devices. Construction safety helmets, however, seem to have only a minimal effect on sound localization.
Application
Results of this study will help stakeholders make decisions that are more informed in promoting safer workplaces.