"Superheterodyne" is a contraction of "supersonic heterodyne", where "supersonic" indicates frequencies above the range of human hearing. https://en.wikipedia.

"Superheterodyne" is a contraction of "supersonic heterodyne", where "supersonic" indicates frequencies above the range of human hearing. https://en.wikipedia.org/wiki/Superheterodyne_receiver https://en.wikipedia.org/wiki/Superheterodyne_receiver