Identical ITDs form a 3D cone producing ambiguous source location.

Evidence

Again assuming a spherical, pinnae-less head, there would be a 3D conical surface extending out of each ear that represents the same ITD on the surface (Mills, 1972). Figure 7–4 illustrates this surface, which is called the cone of confusion, and it should be thought of as extending infinitely into space. The ITD is a relative feature of sound (i.e., it is a difference, not an absolute), and sounds originating from a variety of locations could be perceived as being in the same location. The location of any sound on the cone of confusion could be confused with all other sound locations on that surface. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 1472

Categorization

Category: Definitional Content

• DEFINE: Defines the cone of confusion and why ITD alone cannot disambiguate elevation or front-back.
• QUESTION: Since ITD alone confuses the cone, how do real (pinna-bearing) listeners resolve front-back for low sounds?

Related

• The cone of confusion makes identical ITDs map to many indistinguishable locations (similarity 0.93)
• All sound locations sharing one ITD form an infinite cone of confusion (similarity 0.92)
• A dedicated cone-of-confusion coordinate system describes hard-to-discriminate sound directions. (similarity 0.85)
• The cone of confusion prevents up-down and front-back sound discrimination (similarity 0.85)
• Cone of confusion makes time and level cues ambiguous for elevation (similarity 0.82)
• Front and back sound localization requires other mechanisms than ITD (similarity 0.82)
• Head symmetry creates a cone of directions where sound localization is ambiguous (similarity 0.81)
• Head movements and pinna shape resolve ambiguous sound localization (similarity 0.81)
• Pinnae shape the sound spectrum to encode elevation and front-back position (similarity 0.80)
• Interaural time delays alone cannot fully determine sound source direction (similarity 0.80)
• Head movements resolve front-back ambiguity by creating direction-specific binaural cue changes (similarity 0.79)
• The outer ear’s resonant shapes enable front-back sound localization (similarity 0.79)
• Head movement and pinna shape resolve cone-of-confusion ambiguities (similarity 0.79)
• Phase delays beyond 180 degrees make direction judgments ambiguous (similarity 0.79)
• Interaural timing alone cannot explain our sound localization ability (similarity 0.78)