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 illustration, you can manipulate the different features of a tone to see how interaural time differences contribute to our perception of auditory direction.
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:
Play: will play to tone with the current settings listed below.
Play Series: will play a series of tones that will systematically vary the delay between the two ears.
Delay: change the delay begtween when the tone will be delivered to each ear.
Frequency (Hz): change the frequency of the tone.
Duration (ms): the duration of the tone in milleseconds.
Pressing this button restores the settings to their default values.