One of the underappreciated parts of automated machining is that the steppers and drive elements will sing you a little robot song while they work. Especially with lasers - it's there on CNC mills, but the cutter is a wall of blaring noise that tends to overwhelm everything else whenever it's in contact with the workpiece. A straight line is a simple tone, changing slightly depending on which way it's going and which components are doing the most work; circles are a wild whoop as it cycles through every direction; a complex cut causes kind of a fussy little syncopated grunting and whistling as the head wiggles back and forth. After a little while you can tell exactly where it is on a design from across the room.