Interaural level differences grow with frequency and side placement

Evidence

As a result, the level difference (in dB) between the two ears, the interaural level difference (ILD) varies as a function of frequency and location of the sound source. … For all frequencies tested, the ILD was 0 dB when the sound source was directly in front or in back of the listener. • The ILD was greatest when the sound source was 90° to the side of the listener. • The size of the ILD increased as frequency increased. The ILD can be as large as 20 dB for high frequencies (>4000 Hz), particularly for sounds located to one side of the body. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1455

Categorization

• DEFINE: Defines interaural level difference (ILD) as the dB difference between the two ears and gives its measured frequency/azimuthal behavior.
• XREF: connects to: Interaural level differences only emerge at frequencies above roughly 400 Hz. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1434; Directional hearing rests on interaural time and intensity differences. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 704