I'm 15 at the end of this October. I don't squeak, in fact I have a fairly deep voice for my age. My friend's mother thought I was thirty when I called his house and wouldn't let me talk to him because of it, but I digress. I believe what counts is attitude and maturity, in other words one's mental age*. I'm positive none of you readers wouldn't have guessed my age by my excellent spelling and grammar, eh?
*note when I say attitude, maturity, and mental age, I am referring to teenagers and not.. How should I put this.. Adults who have yet to grow up?