Ear separation on one axis makes horizontal binaural cues strongest

Evidence

The most relevant binaural cues to the human listener lie in the horizontal plane and differ only in their azimuth (e.g., whether a sound is closer to the left or right side of the body). This is true as our ears are only separated from each other on the horizontal dimension: They are in the same location with respect to elevation (neither ear is higher than the other) and they are in the same location with respect to the front/back plane (neither ear is closer to the front of our bodies than the other). If we assume that the head is a sphere and has no pinnae, the acoustic cues across the ears would provide information about only azimuthal location. However, we should note that our pinnae are asymmetric in both of those planes, and they (along with our bodies) alter sound in subtle ways that influence our binaural auditory perception. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1444

Categorization

• XREF: Sets up why pinnae (monaural cues) are needed for front/back and elevation disambiguation — relevant to the pinnae section mentioned here. — connects to: Binaural microphones capture exact tympanum signals but depend on one’s own head shape; Head separation between ears produces arrival-time and intensity cues for direction; Basic binaural cues cannot fully explain front-back and elevation judgments (+1 more)
• corroborated: 2 independent passages support this claim — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1444

Broader Connections

• Head separation between ears produces arrival-time and intensity cues for direction #expands (0.85)
• Binaural sound localization depends on ear-level temporal and intensity encoding efficiency #expands (0.80) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 70
• Basic binaural cues cannot fully explain front-back and elevation judgments #qualifies (0.72)