Comparison of sound propagation and perception of three types of backup alarms with regards to worker safety

Abstract

A technology of backup alarms based on the use of a broadband signal has recently gained popularity in many countries. In this study, the performance of this broadband technology is compared to that of a conventional tonal alarm and a multi-tone alarm from a worker-safety standpoint. Field measurements of sound pressure level patterns behind heavy vehicles were performed in real work environments and psychoacoustic measurements (sound detection thresholds, equal loudness, perceived urgency and sound localization) were carried out in the laboratory with human subjects. Compared with the conventional tonal alarm, the broadband alarm generates a much more uniform sound field behind vehicles, is easier to localize in space and is judged slighter louder at representative alarm levels. Slight advantages were found with the tonal alarm for sound detection and for perceived urgency at low levels, but these benefits observed in laboratory conditions would not overcome the detrimental effects associated with the large and abrupt variations in sound pressure levels (up to 15-20 dB within short distances) observed in the field behind vehicles for this alarm, which are significantly higher than those obtained with the broadband alarm. Performance with the multi-tone alarm generally fell between that of the tonal and broadband alarms on most measures.

Noise as an explanatory factor in work-related fatality reports

“…[ 14 16 17 18 19 20 ] According to three explanatory models[ 21 22 23 ] and empirical data, there is a biological plausibility for a causal relationship between noise exposure and occupational accident risk. [ 22 24 25 26 ] These published models have been integrated in a new model [ Figure 1 ]. Ambient noise interference with communication appears as a main plausible pathway.…”

Directivity of hearing of auditory danger signal emitted by overhead crane

“…The study finding that the effectiveness of reception of a tonal warning signal of vehicle backup alarm is the lowest and is greatest for a wide-band signal, while a signal consisting of multiple tones is received with intermediate effectiveness, also indicates that the type of sound signal may have a significant impact on the ability to receive it [13].…”

Assessment of the audibility area of auditory danger signals produced by industrial truck

“…Odbiór dźwięko-wego sygnału bezpieczeństwa jest możliwy jednak wtedy, gdy zostanie on odpowiednio zaprojektowany [4][5][6][7]. Należy także mieć na uwadze, że praca w hałasie o wysokim poziomie często wymaga stosowania ochronników słuchu, co może jeszcze bardziej pogorszyć odbieranie dźwiękowego sygnału bezpieczeństwa [4,[8][9][10][11].…”