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.

Absence of the P waves and, eventually, a "sine wave" pattern (see below), which is frequently a fatal rhythm. Enlarge . Giving IV calcium is "cardioprotective" in the setting of hyperkalemia.