Binaural beats, tritone paradox, pitch and tempo circularity, wason effect for faking high performance audio, biological audio effects, and using missing fundamentals for playback on phones and low-quality devices? Casey Connor demonstrates some fascinating audio effects and illusions in his multi-part series of audio illusions and effects. Some of them are used to simulate high performance playback on cheap devices like phones. Good headphones are required for some of them.

Here’s the first video go get you started: