Sotto voce (/ˈsɒtoʊ ˈvoʊtʃi, -tʃeɪ/,[1][2] Italian: [ˈsotto ˈvoːtʃe]; literally 'under the voice')[3][4] means intentionally lowering the volume of one's voice for emphasis. 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]
sotto voce. (It., lit. "under the voice.")
sotto voce ... Under the voice, in soft voice