My iPhone and iPad screens turned on at the same time and my iMac made a bleep noise?

[Gapplehelp]

I have no idea what just happened, has this ever happened to anyone else? This is my first time here so apologies if this is in the wrong forum.

 

[JackieInCo]

Sounds like they are notifications that don't make it through.

I have this happen all the time on my iPhone/iPad. How do I know these are notifications? Because I actually get the notifications on my Android phones at the same exact second.