Early Skype 8 versions rang through the default device even if you changed the speaker device to something else. I have not retested that in quite some time.

I really like Skype 8, and have been using it for months exclusively; but one problem I do have with it is that incoming call sounds still come through when I have set myself to Do Not Disturb. Letting you know this in case it
affects your broadcasting plans at all.

On Fri, Oct 12, 2018 at 06:55:37AM -0700, Nick Giannak III wrote:
Hello all.
I'm sending this here because I suspect some of you have contact with
Microsoft. I upgraded to Skype 8, and I honestly find it not bad at all
accessibility-wise, far from the horror show it was depicted as. I can
even use it with speed, which isn't always easy to do in this day and
age. I'm even going to find out how it does on air in a few hours...And
here's the rub.
Is there any way to have Skype 7 behavior, wherein Skype will ring
through one sound device, but not the same one as conversations play?
I do appreciate that this is lightyears better than Skype 8 was when it
came out, based on things I've seen. I hope it continues to get better!
Thanks,
Nick


References

1. https://groups.io/g/skypeenglish/message/3422
2. mailto:skypeenglish@groups.io?subject=Re:%20%5Bskypeenglish%5D%20Skype%208%20ringing%20device
3. mailto:nick@...?subject=Private:%20Re:%20%5Bskypeenglish%5D%20Skype%208%20ringing%20device
4. https://groups.io/mt/27270759/409874
5. https://groups.io/g/skypeenglish/post
6. http://www.dlee.org/skype/
7. https://groups.io/g/skypeenglish/editsub/409874
8. mailto:skypeenglish+owner@groups.io
9. https://groups.io/g/skypeenglish/leave/defanged