Here's a breakdown:
* Sans: French for "without"
* Voce: Italian for "voice"
Therefore, "sans voce" literally translates to "without voice."
It's essentially the same as the Italian term "sotto voce," which also means "softly" or "in a low voice."
Example:
If a musical score instructs a singer to sing a particular section "sans voce," it means they should sing it very softly and delicately, almost as if they are whispering.