Real Dictionary

voice
When someone speaks or sings, you hear their voice.
countable noun: Someone's voice is their opinion on a particular topic and what they say about it.
singular noun: If you have a voice in something, you have the right to express an opinion on it.
singular noun: In grammar, if a verb is in the active voice, the person who performs the action is the subject of the verb. If a verb is in the passive voice, the thing or person affected by the action is the subject of the verb.
verb: If you voice something such as an opinion or an emotion, you say what you think or feel.

voice in American English
sound made through the mouth, esp. by human beings in talking, singing, etc.
noun: the sound or sounds uttered through the mouth of living creatures, esp. of human beings in speaking, shouting, singing, etc

voice in British English
noun: the sound made by the vibration of the vocal cords, esp when modified by the resonant effect of the tongue and mouth