Since I'm out of puberty, that isn't the reason for why my voice changes. I usually notice that on occasion my voice changes after groggily waking up, where the pitch of my voice has gone deeper.
I talk in higher pitch to girls, little kids, non-school non-business older folks. I sometimes do it unintentionally sometimes i do it purposely. It gives them the idea that I'm a gentle person. Sometimes its annoying sometimes its not X.X. Low pitch to guys.
My mood is a key factor on how my voice comes out. But it's just subtle changes nothing much. Heck I only know this since people I know point it out. :roll: