The speaker gives the impression of uttering involuntarily a truth which may surprise, shock, or offend.
Galileo Galilei's (probably apocryphal) utterance "Eppur si muove" ("And yet [the Earth] moves"), spoken after deciding to recant his heliocentric theory, is a legendary example of a sotto voce utterance.
[5] In law, "sotto voce" on a transcript indicates a conversation heard below the hearing of the court reporter.
[6] In drama, literature, and rhetoric, sotto voce is used to denote emphasis attained by lowering one's voice rather than raising it, similar to the effect provided by an aside.
Also similar to an aside, sotto voce can be used to express a character's thoughts out loud.