Rotating Chains by Akiyoshi Kitaoka. The guy must be insane. Visit his website for an hour and you will be too! You’ll be doing very well to get past the first page. It says “Warning: This page contains some works of “anomalous motion illusion”, which might make sensitive observers dizzy or sick.” I looked at his first page for 5 seconds just now and I still feel disturbed. The reigning master of optical illusions.
Audio illusion: A rock feel that keeps getting faster..but doesn’t seem to be getting any faster.
Audio illusion: There’s a tone with gaps in it. When the noise gets loud enough, the gaps seem to disappear.