Low-frequency ILD serves as a distance cue and coherence detector

Evidence

As noted earlier, plane waves do not generate ILDs when their wavelengths are long compared to the size of the human head. The question then remains, why are we sensitive to ILD at low frequencies? There are at least two reasons for this. At low frequencies, the ILD is clearly a distance cue, since when the source reaches the listener, much higher ILDs are measured between the ear canals. The other use of the ILD seems to be in the perception of coherence of ear canal signals. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1443

Categorization

Category: Causal Relationships

• XREF: Connects to the puzzle of why human hearing is far more capable than plane-wave physics predicts — parallels the chapter’s earlier theme that spatial hearing exceeds what simple binaural-cue physics alone would require.

Related

• Low-frequency interaural level differences cue source distance and signal coherence. (similarity 0.91)
• Humans perceive interaural level differences at frequencies where plane waves produce none (similarity 0.85)
• Low interaural coherence makes sound events seem diffuse and surrounding (similarity 0.82)
• Interaural level differences only emerge at frequencies above roughly 400 Hz. (similarity 0.80)
• The ear can perceive ILDs even where they never occur naturally. (similarity 0.80)
• Coincidence detection models were extended to also encode ILD sensitivity (similarity 0.80)
• Cortical intensity encoding becomes ear-independent through strong interhemispheric connections (similarity 0.79)
• The head shadows and reflects sound to create level differences between the ears. (similarity 0.79)
• Binaural detection advantages act on small spectro-temporal units, not whole frequency bands (similarity 0.79)
• Exaggerated interaural level differences signal that a sound source is near (similarity 0.78)

Broader Connections

• Short time frames make ILD estimates sensitive to interaural coherence #expands (0.85) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1679
• Coincidence detection models were extended to also encode ILD sensitivity #responds-to (0.78) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1673
• Rayleigh’s duplex theory links ILDs to high and ITDs to low frequencies #qualifies (0.75) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1451
• High-coherence stimuli bind pre-attentively while low-coherence ones need attention. #exemplifies (0.72) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5137