Comparison of discomfort caused by two types of backup alarm

Abstract

Nowadays used on most of construction vehicles, tone backup alarm causes a strong discomfort among resident citizens. To solve this problem, "CETIM" (Mechanical Industries Technical Centre) decided to characterize and test another kind of alarm. This one is called "Cri du Lynx" in french (Lynx scream) because of its particular sound looks like a white noise. A previous study showed that the average sound level of the noise-alarm detectability is 67 dB (A) while it is 64 dB (A) for the tone-alarm (in a 80 dB(A) background noise). However, the noise-alarm could be used if it is less disturbing than the tone-alarm. The present work aims to compare the discomfort caused by exposure to tone and noise back-up alarms. About 50 people rated 2 times the discomfort caused by 11 sound environments. Each sound environment consisted of a site construction sound environment set at about 65 dB (A) mixed with a sequence of tone or noise alarm set at 56, 59, 62, 65 or 68 dB(A). One of the 11 stimuli had no alarm. Through an ANO V A it can be said if the kind of alarm and / or the sound level has an influence on the discomfort. © 2013 Acoustical Society of America.