Requires the ‘Bang & Olufsen’ integration: https://github.com/bang-olufsen/bangolufsen-hacs
A Blueprint for this scenario: https://youtu.be/AiZbrYQ6u48
Simply select the speaker you want announcements from. Allows for custom phrases as well; default is “Joined <friendly name>”, but if you want it in e.g. danish it can easily be modified to “Lytter med fra <friendly name>”.
It is also possible to enable announcements when using a remote or the app to expand.
You will need to create an automation for each Mozart-speaker you want to announce.