Listen to this video until the end, and when it stops, play it again to hear the difference. A Shepard tone, named after Roger Shepard, is a sound consisting of a superposition of sine waves separated by octaves. When played with the base pitch of the tone moving upward or downward, it is referred to as the Shepard scale. This creates the auditory illusion of a tone that continually ascends or descends in pitch, yet which ultimately seems to get no higher or lower. It has been described as a "sonic barber's pole".
Daniel Hashimoto just wants his kid's dreams to come true, at least a little. Earlier this year, we first saw James, aka Action Movie Kid, in a hit viral video created by the wizardly dad who's an After Effects artist at DreamWorks Animation in Los Angeles.