Explain these quotes for me? Of Mice and Men. Visual and Auditive Imagery.?

Man I hope you read the book because it is pretty good. Yeah, if I remember right these are auditive and visual imagery. You can almost hear the gunshot and see the river, it pulls you into the scene and adds depth to the book. John Steinbeck was a master at this. Oh, and it sounds better than, "the gun went boom" and, "they looked at a river."