voix
voice; vocal sound (produced by speaking or singing)
Baisse le ton, ta voix est beaucoup trop forte.
Lower your tone, your voice is way too loud.
vote; suffrage (one's vote in an election or decision)
grammatical voice (e.g., active vs. passive)
Cette phrase est à la voix passive.
This sentence is in the passive voice.
opinion or the right/influence to be heard (to express one's view)
Notes
GENERAL INFO
Voix (f.) means "voice." It is a feminine noun in French.
USAGE
It refers to sound produced from the mouth (e.g., "avoir une belle voix" - to have a beautiful voice), or the grammatical concept of "voice" (e.g., "la voix passive" - the passive voice).
TRAPS
Don't confuse voix (voice, sound) with voie (way, path, lane). They are homophones (sound identical) but have completely different meanings.
