Where’s
the top?
Push the button and listen. The tone keeps climbing, and so do the stairs. See if you can find the top.
Sound starts when you push the button.
Tap a lantern, or a numbered lamp, to switch that tone off.
The readout
Every line is one tone.
Each tone climbs, gets quiet near the top and slips back in at the bottom, quiet again. Your ears follow the loud ones in the middle, so all you hear is the climb.
Switch off Hide the handoff and watch the lines: now every tone stays loud right to the top, and you can hear it drop back down.
How the trick works
A climb that goes in circles.
Six tones at once
Each one is an octave above the next, so together they blend into one sound. They all rise together.
Loud in the middle
A tone fades out as it nears the top, and comes back in at the bottom just as quietly. You never hear the swap.
Pull it apart
Switch tones off with the lamps, or press Solo and pick one. Follow a single tone up the stairs and watch it disappear.
Dunkirk mode
Tension that never lands.
Christopher Nolan has said he wrote the script for Dunkirk around this same idea, and Hans Zimmer’s score is built on it, along with the ticking of Nolan’s own watch.
Our Dunkirk mode is our own take, made from the tones on this page. A ticking clock joins in and seems to speed up forever, using the same trick for rhythm. There’s no film audio here.
Where it comes from
Roger Shepard, 1964.
Roger Shepard described these tones in Circularity in Judgments of Relative Pitch, made by computer at Bell Labs. The smooth, gliding version you’re hearing is known as the Shepard–Risset glissando, after Jean-Claude Risset, who also made a rhythm version. More about the effect ↗
How strong the effect is depends on the listener and the speakers. Headphones help. The lanterns and the readout show the same trick with the sound off.