EventOwner An Exact Marginal Pilot of Audio Visual Source Ownership

Two audio-visual pairs can contain the same global event inventory while assigning sounds to different visible sources. We construct a small procedural test that makes this relationship necessary for classification. Two event schedules drive rendered rotating objects and four-channel waveforms. Crossing video and audio ownership assignments gives four pairs per scene; every exact video and waveform occurs under both labels. A frozen confirmation study contains 120 scenes and 480 dependent pairs in held-out procedural families. A frequency-resolved joint diagnostic obtains balanced accuracy 0.806, compared with 0.771 for a broadband joint diagnostic, 0.500 for temporal synchrony, and 0.510 for pooled spatial coverage. Scene-cluster intervals preserve the repeated-pair structure. Both joint methods have identical paired-ranking accuracy of 0.996, and performance weakens under overlapping activity and near-colocation. An exploratory 72-window real-recording comparison is inconclusive and favors a simpler spatial reference. The result supports controlled joint construction and evaluation feasibility. It does not establish realistic acoustics, learned source understanding, or real transfer.