The impact of headtracking on intelligibility in a multitalker display

Although overall performance in multichannel speech monitoring tasks is known to improve substantially when the apparent locations of the competing talkers are spatially separated with a virtual audio display, the impact that real-time interactive headtracking has on these tasks is not yet well understood. In this experi-ment, listeners were asked to monitor four simultaneous spatially-separated speech signals and to identify the contents of a target phrase that was addressed to a pre-assigned call sign. This task was performed with and without interactive headtracking, with wide (60) and narrow (20) spatial separations between the competing talkers, and with four different probabilistic models for changes in the location of the target talker. The results indicate that interactive headtracking cues have a significant effect on multitalker listening performance only in situations where the target talker tends to remain in the same location for more than one consecutive stimulus presentation, and that the addition of interactive headtracking cues in these situations can either improve or degrade overall performance depending on the size of the angular separations between the competing talkers in the virtual environment