The 16 year old is struggling with his h...
Bieber admits he is also counting on his music mentor Usher, who began singing professionally at the age of 11, to guide him through the trying time.
He tells Vibe.com, "Everyone's voice changes. Puberty is a natural thing. I have the best vocal coach in the world and we're working on my voice and doing what I need to do. It's not like as soon as you hit puberty you stop singing. Usher is the best mentor in the world and he survived puberty. He tells me what to do, what not to do."
