What is the name for the auditory illusion of a note that seems to be rising infinitely?

The name for the auditory illusion of a note that seems to be rising infinitely is Shepard Tone. This illusion is created by overlapping multiple tones that are separated by an octave. As the tones ascend, the lower tones decrease in volume while the higher tones increase, creating a continuous rise in pitch perception. This effect is named after its creator, cognitive scientist Roger Shepard, who first introduced it in 1964. The Shepard Tone has since been used in various forms of media to create the impression of infinite ascension or tension in music, sound effects, and even in film scores.