Chromatic Illusion

Get a set of headphones–you’ll need them for this audio high. Listen closely to the patterns. Once you’ve listened with both ears for thirty seconds, press STOP. Now remove the headphones from one ear and just listen to the pattern in the other. Do the same for the other side. Listen to them together. Whoa. Whoa!

How It Works

Chromatic Illusion incorporates two scales that range over two octaves. One scale goes up while the other goes down, with a single tone switching from ear to ear. When played together, some people hear a high scale and a lower scale moving up and down and meeting in the middle every few seconds. Others don’t hear scales at all, but random bleeps and bloops. It all depends on how your brain is wired, and how it wants to interpret the tones. Chromatic Illusion becomes even more confusing and fascinating when, after listening to the tracks together, the stereo tracks are played back individually to each ear. You’ll hear what we mean.

This audio high was developed by psychology professor and audio-explorer Diana Deutsch who has been experimenting with sound hallucinations in an attempt to uncover how our brains process audio signals. In her research, Deutsch has demonstrated how people can hear completely different patterns in the same set of repeated sounds. It’s like how the Carpenters’ four-minute-and-twelve-second, painfully slow, wrist-cuttingly depressing version of “Ticket to Ride” sounds so good to some folks (like us) and like dog poop to others (fools). It’s also why Chromatic Illusion will sound so different to different people–it all depends on how your particular brain is wired.

Chromatic Illusion © Diana Deutsch, 1995. Learn more about Deutsch’s amazing work at http://philomel.com