Virtual barber shop

A barber seems to move around your head, with scissors and clippers sounding startlingly close to your ears.

Put on stereo headphones with the left and right sides correctly placed. Play the listening demonstration, keep both channels separate, and close your eyes if you like. Listen for the barber moving behind you and the scissors approaching each ear.

Your brain locates sound using tiny differences in arrival time and loudness between your ears, plus the way your head and outer ears filter it. Binaural audio reproduces these cues in two headphone channels, making the barber seem to occupy the space around you. Spatial sound is the broader idea of placing sounds in three-dimensional space; binaural playback is one way to deliver it. The strength of the illusion varies between listeners.