Hi @Prod ,
Recently Ring pushed a firmware update so now all the Ring Video cameras have a Siren now (but not on some Ring Video Doorbells). Unfortunately, it is not a very loud siren sound.
The siren can be easily be activated manually (without setting off the Alarm Base Station) by tapping on the white"Double-Parenthesis-Exclamation Point" Icon in the video display (very different Icon from the RED"Exclamation Point" Icon which does activate the Alarm Base Station).
But as @icadam pointed out, all these camera sirens are not activated by the Alarm Base Station automatically if an intruder breaks in, so hence his request for that feature. It would be very cool to have a tripped Alarm Base Station automatically activate the sirens in all the cams. 