I’ve just purchased ring alarm and I’m absolutely astonished to find out that this does not connect to my existing ring outdoor cameras so when the alarm sounds the sirens on the cameras remain quiet??? please work on this necessary feature.
Also the indoor camera that came with my alarm kit does not activate motion alarms Again I am absolutely astonished that the camera that is so sophisticated to have motion alerts to my phone cannot activate the siren on the alarm and outdoor cameras
Unfortunately, the Ring Alarm system can only currently activate the sirens on the Alarm Base Station, and Keypads, and the indoor non-weather-resistant Dome Siren. 
But you aren’t alone in wanting an external siren! Many others want an outdoor weather-resistant siren, or some ability to connect an exterior siren, or some way to have a siren sound outdoors . The more “Thumbs Up” Kudo votes they see there will better get their attention, increasing the chances of getting siren sounds outdoors. You should click the related links below and add your Kudo vote, if you like the requesting author’s idea (add your “Thumbs Up” Kudo vote on the left side of the author’s starting post), to help get the attention of the Ring Teams.
Submitted by Hamster1 :
https://community.ring.com/t5/Feature-Request-Board/External-Siren/idi-p/67621
Submitted by DrTej and several others (similar requests merged into this request):
Submitted by Jayfalcon22 :
https://community.ring.com/t5/Feature-Request-Board/Link-Siren/idi-p/64706
Submitted by Brumey :
Submitted by Paul209 :
https://community.ring.com/t5/Feature-Request-Board/Alarm-camera-siren-integration/idi-p/69879
Submitted by abc :
Submitted by Doug_in_Calgary :
Submitted by THESPEC1ALONE :
https://community.ring.com/t5/Feature-Request-Board/External-alarm/idi-p/36839
Ring are blatantly advertising that as a feature. Hopefully it’s imminent, and not just on their website to bump up sales during the current promotions. Take a look at the Linked Devices picture on their website.
Thanks for the info, I have also liked all the links
They have now removed the screenshot showing the siren activating when the alarm is triggered. The screenshot showed the floodlight cam, but hopefully spotlight cam will also get this feature.
I sent this to their Social Team last year and they said they’d pass it on.
This is definetely a much needed feature!
I’ve been wanting this for years now. Ring please add this integration.
@jonscarpa
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@shahinfard
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@F1N1
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@Paul209
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@Bungle
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Thanks to @DanHolloway who noticed the new feature and posted in one of the other “Feature Request Boards”, Ring listened and did it! I got all excited so I immediately went to my Ring App to link mine also! But, I was briefly disappointed when I tried to do it because I did not initially see any change in the App. It initially appeared to still only make the cameras record when the alarm sounded . . . until I looked more closely. So, yes, the camera sirens CAN be linked now by:
Menu > Devices > Alarm Base Station > Base Station > Linked Devices > Alarm Sounding >
After selecting "Alarm Sounding", this is where I was briefly disappointed because I thought it was still just to select the cameras to only record. Then I noticed the "Explanation-Point" Icon, just right of the "Camera" Icon. Now I understood that by selecting this "Explanation-Point" Icon, it links the camera's siren to the alarm too! So after selecting "Alarm Sounding" then:
Select “Explanation-Point” Icon for the cameras you wish to sound off their siren with the Base Station > then “Save”.
Wonderful! Thank you Ring! 
Thanks for the updates. I’ve just been able to link my spotlight and stickup cam sirens
Great job from Ring and I’m glad we now have this additional layer of security.
I still think an external siren would be good for those of us that don’t want a large camera at the front of the house, for example UK home would have the video doorbell but not a security camera at the front.
Thanks again to Ring.
Great Job Ring - thanks for enabling integration between the base station (in alarming mode) so that my floodlight cam sirens all sound too - perfect