A single active speaker creates an interaural time delay that listeners localize.

Evidence

The Phase Shift Produced when Only One Speaker Is Active, Resulting in an Interaural Time Delay (ITD) Corresponding to the Loudspeaker’s Location FIGURE 7. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2198

Categorization

• DEFINE: Defines ITD — interaural time delay — as the phase shift between ears when only one speaker is active, the mechanism behind directional hearing.