I can tell my dog pays attention to the details. I came home tonight in the rental car, which I rapidly nicknamed the Tank. As I pulled in to the driveway and turned off the engine I heard the sound of barking from my house. Lindy does not bark a lot, and definitely not when I come home. Apparently she could tell it was not my car pulling in the driveway and decided to defend her territory. I don't know that I can tell much difference in the sound of engines. However I never claimed to have good hearing, and definitely not as good as dogs . . .