Head motion and latency compensation on localization of 3D sound in virtual reality

Proceedings of the ACM symposium on Virtual reality software and technology - VRST '97 (1997), pp. 15-20, doi: 10.1145/261135.261140
Experiments
Tasks
Findings

Considering a typical architecture walkthrough system that can generate 3D sound as well as graphical objects, since the simulated sound has to be- synchronized with the graphics subsystem, whenever there is latency in the graphics subsystem, there is equal amount of latency introduced to the 3D sound system. This experiment describes how latency affects the localization of 3D sound.

Variables and Constants

    Auditory Fidelity
  • latency - without latency compensation and with latency compensation. using a prediction algorithm, they compensate for latency by interpolating between updates. they used a grey system algorithm because of its lower computation complexity than that of the kalman f
Constants

300ms of latency, six initial starting locations for sound

System Info

Displays
None
Input Hardware
None
Software
None

A display was not used, it was a purely aural environment

Participant Info

Total # Age Range Gender Balance
6 -

When a subject hears the 3D sound in space, they are required to trace the 3D sound source by facing towards the sound source, and when the subject was certain that they were exactly facing the sound source, they could press the left button of a mouse to signal their decision. If the azimuth degrees between the head orientation and the sound source was within 5 degrees, the playback of 3D sound stopped. This means that the subject has finished the tracing task. However, if the azimuth difference exceeds the given threshold, the 3D sound played continued to play until they relocalized the source.

Interaction and Environment

Interface

Participants were head tracked, so they looked in the direction they wanted and used a mouse to enter their selection.

The environment was completely aural, no visuals were used.

Dimensionality Scale Density Visual Realism
3D Medium Low Not reported
Metrics

  • time - completion time
  • errors - errors in tracing the sound
  1. There was a significant direct effect of latency on time for a comprehension of spatial information task.

    Latency compensation had a significant effect on reducing mean completion time for 3D sound localization task

    Specificity: Somewhat general
    HRTF was not measured for each participant. They didn't consider sound locations with non-zero elevation, or sound sources at different distances from the participant.