Yeah Justin Bieber's voice didn't change yet
Some males are late bloomers and their voice may take a couple more years to change.
The voice you were born with - each of us has his/her "normal voice".
Bass.
All of them have changed except Eggman's voice actor.
Only males, not females.
Not very! Once a males voice has broken it is depends how low their voice is. Probably 50/50?
he's voice changed when started singing the really high notes or his voice changed like every boys voice changes when they get older.
Can it be changed into passive voice?
androgens
Yes, a kindle has a option to read you the book in either a males voice or a females voice
he better have not
Baritone is the most common voice classification for men.