The brain suppresses equally loud sound in one ear to convey source direction instantly

Evidence

A very clear audio illusion with a definite purpose involves estimating the direction of a sound source. A sudden pulse of sound from the right will arrive at the right ear first. We use such arrival time delays to help decode where the source is, as mentioned in section 21.2. A click from the right side of the head is heard only in the right ear, yet the sound is almost exactly as loud in the left ear after it has diffracted around the head! Our brain suppresses the sound on the left, which is a lie with a purpose: to convey, without delay, the impression that the source of sound is to the right. How else would this information be presented to us so that the conclusion is instantaneously obvious? — Eric J. Heller, Why You Hear What You Hear- An…, 2269

Categorization

• XREF: Connects to Weisskopff’s point from the same book about interaural time delays and Head’s earlier sound localization chapter. — connects to: Occluding one ear in a sound field dramatically reduces binaural loudness summation — Dijk, Pim van, Physiology, Psychoacoustics and…, 1544; Intensity and delay directional cues can cancel each other out in the brain
• QUESTION: What is the actual neural mechanism that suppresses the obstructed-side signal?
• corroborated: 2 independent passages support this claim — Eric J. Heller, Why You Hear What You Hear- An…, 2269

Broader Connections

• Occluding one ear in a sound field dramatically reduces binaural loudness summation #expands (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 1544
• Intensity and delay directional cues can cancel each other out in the brain #expands (0.72)