Sure, opposable thumbs are handy. But in his brilliant new book, “This Is the Voice,” John Colapinto says the voice is our species’ greatest attribute. We rely on it to communicate and collaborate, woo our mates and protect our children, make art and win wars. John would know. A rock ‘n’ roll vocal injury changed his relationship with his instrument and set him on a path to better understand what his voice means to him — and what the voice means to humanity.