Is everyone deaf?

I had not gotten far into this movie when the bad guys feed the lawyer's hand into a shredder and not one person outside of the office heard anything. If my hand was in a shredder I would make a lot of noise. Also, who the heck comes home and finds the front door open and then enters, calling out "who's there?". Anyone I know would back up and call the cops the have them enter and check things out.