I had the opposite problem. We sometimes set a little alarm clock that I have for various reasons. And, because it's not regular, Krypto barked at it.
Then, he started to come and get us when it rang. He acted like we couldn't hear it, lol!
Anyway, I decided to encourage him to react appropriately - ie: come and get us, act excited, but not bark.
The way that I see it, is that he will let us know when something out of our routine is happening, which can be a good thing, depending. I have a friend who has a SD and is deaf. Her dogs have always alerted her to things like doorbells, tea kettles boiling, kitchen timers going off, etc. Since Krypto does it naturally, I figured that it was best to guide and temper his reactions to things like the alarm.
It's hilarious that Charlie keeps you on schedule!
Love All Life, Thank You For Posting! :)