find (one's) voice
1. To find one's distinctive style or vision of artistic expression. I think this is your best story yet, Betsy—you've really found your voice as a writer. It takes time to find your voice, but I'm confident you'll get there by the end of our photography class.
2. To regain the ability to speak, especially after something frightening or startling has happened. It took him a minute, but Pete found his voice again after we startled him at his surprise party.