Speaker
Description
In noisy workplaces, wearing a hearing protection device (HPD) is mandatory but can impair situational awareness and the audibility of environmental sounds. Level-dependent HPDs amplify soft sounds to ensure audibility while still attenuating high-level sounds. However, they can also impair situational awareness, e.g., regarding localization and detection of warning signals. Distance perception is an important part of localization, e.g., in factories or at construction sites, but is rarely investigated with HPDs. In this study, the distance of a reverse warning signal was simulated in eight steps between 1 and 25 m with virtual acoustics for playback in an 86-channel loudspeaker array. Target signals alone and with diffuse pink noise were recorded with an acoustic test fixture with open ears and wearing a level-dependent HPD in three settings. In a listening study, 32 normal-hearing participants had to identify the actual distance of the recorded signals. The results showed impaired performance in all HPD conditions compared to open ears. Moreover, over- and underestimation of target distances varied largely between conditions, indicating risks of misperceptions when switching HPD settings during work.