U.S.O.

Unidentifiable Sound Object: sound that cannot be identified by the listener.

Suspension

Extreme case of null extension, suppression of sounds that are naturally expected in a scene.

Subjective openness

Kind of trance that can be experienced by music listeners, lowering the threshold of belief required to open to the diegetic world.

Archetypal sound

Sounds that are embedded in the human collective unconscious; carrying a kind of semantic meaning with them