Sine Waves Show the Power of Perspective Trigonometry is more than memorizing formulas: It allows us to change the way we see the world By Eugenia Cheng April 10, 2019 11:08 am ET ...

Sine-wave speech can be thought of as a sort of auditory illusion, a sensory edge case in which one’s experience has a clear “before” and “after” moment, like going through a one-way door.