What do you mean voice?

In English grammar, voice doesn't mean the sound you make when you speak. It shows whether the subject of a sentence is doing the action, or having the action done to them.

If the subject is the person performing the action, we use the active voice.

Look at the image above. Do you think she cut her hair, or did she have it cut?

Often, when we're not bothered about who or what carried out the action of the verb, we use the passive voice. In other words, the subject of the sentence refers to someone or something who does not perform the action but is affected by the action of the verb.

Active Voice
Passive Voice
I cleaned the office while you were out. The office was cleaned while you were out.
Paris Hilton switched on the Christmas lights. The lights were switched on.