My Cali misses nothing
However, she is a service dog (hearing) so she sees it as her job.
She know the sounds of the neighbors cars and will "cue me" but not crazily when she hears them, but let a car that is not known to her come near and she is going to let me know about it in a persistent way.
At night she sleeps right next to me and if she hears anything she cues me right away. My neighbor used to go to work at 5:00 in the morning and trying to teach her it was alright and she did not have to wake me up was one of my biggest training tasks. She is better with it now, but still move up close to my ear around 5:00 am "just because".
If some one broke into the house I don't thing at 4 pounds anyone would see her as a threat though. Guess that is Smith & Wessons job.