History: What is the Interaural Time Delay?

What is the Interaural Time Delay?

• A sound moving towards us has a higher pitch, a sound moving away has a lower pitch.
  That is the Doppler effect.
• The technique of shifting the amplitudes of a sound source between sound channels.
  That is panning.
• The delay between ears which informs our sense of space of the sound.
  Yes!
• The technique of setting a sound in three-dimensional space.
  That is spatialization.