A silent GIF of a pylon skipping rope went viral because thousands of people could hear it thud. Researchers call the phenomenon vEAR, visually evoked auditory response, and surveys suggest 20 to 30 percent of people experience some version: motion arriving with faint synchronized sound.
Its prevalence makes it an outlier among cross-sensory experiences, common enough that it may be better read as ordinary audiovisual prediction leaking into awareness than as rare wiring. Movement usually makes noise; the brain fills the silence.
vEAR runs the direction opposite to chromesthesia, vision producing sound, and its scale hints that mild synesthesia-like traits are far more widespread than formal counts imply.