Earcon
Also said as Audio icon, UI sound, Notification sound
A short abstract sound with a learned meaning, like a menu blip that means yes. It is a word in the game's language, and nothing in the real world sounds like it.
It tells you something happened while you are looking elsewhere. A good one takes one or two hearings to learn, and then you recognise it for the rest of the game.
Say it
“Confirm is two notes rising a fifth, back is the same two falling, and error is one low note repeated. All under 300 ms, all from the same synth.”
Where you’ve seen it
The Legend of Zelda plays a short rising jingle when you find a secret, and it means the same thing across decades of the series.
Not to be confused with auditory icon
An auditory icon sounds like its meaning: a paper crumple for the bin. An earcon has no natural link, so its meaning is taught through use.