ITD and IID Cues

The degree to which these cues are effective is dependent on the frequency content of the sound.

Both ITD and IID are ineffective at low frequencies (below 270 Hz), and thus the direction of such sounds is more difficult to determine.

ITD Cues

• less precise behind a listener because the change in the ITD per degree in location change is smaller.
• most effective between 270 and 500 Hz
• little contribution above 1400 Hz

IID Cues

• less sensitive to sound sources behind the head.
• very small for frequencies below 500 Hz
• contribute more at higher frequencies
• dominate at (and above) about 1400 Hz