The interaural time difference is the time interval between when a sound enters one ear and when it enters the other ear. In principle, this is a rather straightforward concept. A sound coming to us from the left will enter our left ear a split second before it enters our right ear. A sound coming to us from the right will enter our right ear a split second before it enters our left ear. Because our auditory system can detect this millisecond difference in timing, we can use the interaural time difference to determine if a sound is coming from the left or right. Thus, the interaural time difference gives us the location of the object along the azimuth.
In this activity, you can explore how sounds arising from different direction lead to this auditory space cue.
To see the illustration in full screen, which is recommended, press the Full Screen button, which appears at the top of the page.
Below is a list of the ways that you can alter the illustration. The settings include the following:
Start: Start an animation that traces the sound from the source to the two
ears. This travel time will be plotted on the screen as well.
Sound Source X Position: Move the sound source left and right across the screen.
Sound Source Y Position: Moves the disparity object up and down on the screen.
You can also move the sound source by clicking and dragging on the screen with a mouse or by touching the screen.
Pressing this button restores the settings to their default values.