Sotto voce (ˈsotto ˈvoːtʃe, literally "under voice") means intentionally lowering one's voice for emphasis. The speaker gives the impression of uttering involuntarily a truth which may surprise, shock, or offend. Galileo Galilei

Galileo Galilei

Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...

's (probably apocryphal) utterance "Eppur si muove" ("Nonetheless, [the Earth] does move"), spoken after recanting his heliocentric theory

Heliocentrism

Heliocentrism, or heliocentricism, is the astronomical model in which the Earth and planets revolve around a stationary Sun at the center of the universe. The word comes from the Greek . Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center...

, is an example of sotto voce utterance.

In music, sotto voce

Dynamics (music)

In music, dynamics normally refers to the volume of a sound or note, but can also refer to every aspect of the execution of a given piece, either stylistic or functional . The term is also applied to the written or printed musical notation used to indicate dynamics...

 denotes a dramatic lowering of the vocal or instrumental volume — not necessarily pianissimo

Dynamics (music)

In music, dynamics normally refers to the volume of a sound or note, but can also refer to every aspect of the execution of a given piece, either stylistic or functional . The term is also applied to the written or printed musical notation used to indicate dynamics...

, but a definitely hushed quality. An example of sotto voce occurs in the Lacrimosa

Lacrimosa (Requiem)

The Lacrimosa is part of the Dies Irae sequence in the Requiem mass. Its text comes from the 18th and 19th stanzas of the sequence. Many composers, including Mozart, Berlioz, and Verdi have set the text as a discrete movement of the Requiem.-Latin Text:...

 from Mozart's Requiem Mass in D Minor. The singers lower their volume for emphasis.

In literature, drama, and rhetoric, sotto voce is again used to denote emphasis attained by lowering one's voice rather than raising it, similar to the effect provided by an aside

Aside

An aside is a dramatic device in which a character speaks to the audience. By convention the audience is to realize that the character's speech is unheard by the other characters on stage. It may be addressed to the audience expressly or represent an unspoken thought. An aside is usually a brief...

.
For example, in Chapter 4 of Jane Eyre

Jane Eyre

Jane Eyre is a novel by English writer Charlotte Brontë. It was published in London, England, in 1847 by Smith, Elder & Co. with the title Jane Eyre. An Autobiography under the pen name "Currer Bell." The first American edition was released the following year by Harper & Brothers of New York...

, Charlotte Brontë

Charlotte Brontë

Charlotte Brontë was an English novelist and poet, the eldest of the three Brontë sisters who survived into adulthood, whose novels are English literature standards...

uses the term sotto voce to describe Mrs. Reed's manner of speaking after arguing with Jane:

'I am not your dear; I cannot lie down. Send me to school soon, Mrs. Reed, for I hate to live here.'

'I will indeed send her to school soon,' murmured Mrs. Reed, sotto voce; and gathering up her work, she abruptly quitted the apartment.

In law, "sotto voce" on a transcript indicates a conversation heard below the hearing of the court reporter.

Use of the "sotto voce" can also accompany the art of sarcasm, that is, "ridicule or mockery is used harshly, often crudely and contemptuously, for destructive purposes." "Sotto voce" can also bespeak of a passive-aggressive nature. Person A makes a statement. Person B says, "Yeah, I agree. – sotto voce -- ‘’(what a game)"