The following is full of spoilers from the novel involving Shockwave. If you don't wanna get spoiled then GTFO. After reading the book it hit me. Shockwave barely ever if at all speaks...l. Only twice does he try to talk and thats when he tells the driller to take down the sky scraper the mercs, Sam and carly were in. I'm not even sure if he actually said. The only other time he tried to talk was when optimus punched him so hard in the face it knocked his jaw off. I think Shockwave is so ruthless, emotionless and mission driven that he only talks when it seems necessary. Such as giving an order to the driller or actually about to die.