Investigation of System Latency Detection Threshold of Virtual Auditory Display

It is important in a virtual auditory display (VAD) system to repro-duce not only static sound information, but also dynamic variation of sound. Thus, to achieve a highly precise virtual auditory dis-play system, the system should be responsive to a listener’s head movement. However, system latency (SL), in which the listener’s head movement is reflected in the sound, certainly exists. If SL is detectable to the listener, it results in incongruousness. Conse-quently, the detection threshold (DT) of SL must be well inves-tigated and SL should be sufficiently smaller than it. However, there have been relatively few studies on the DT of SL. Moreover, as inter-subject differences have been reported, it is necessary to examine DT in more detail. In this study, the DT and difference limen (DL) were investigated using two kinds of experiments and compared. As a result, averaged DT and DL over listeners were estimated to be 94 ms and 70 ms, respectively. Moreover, a strong correlation between the DT and DL (r=0.81 (p <.01)) was ob-served. This may mean that DL can be regarded as DT when the minimum system latency of the system is sufficiently small. Therefore, by taking the average of our results and previous stud-ies, DT of SL was estimated as being around 75 ms. 1