End user doesn't need to add an additional service as it exists. Yes. However it's not local and is cloud dependent which was the original question from @CrisD
There was an interesting project for SmartThings that worked well and cached the mp3 files for reuse. PolyTTS and there was BigTalker but I haven't seen it mentioned in a long time.
This Zooz siren says it can play your own audio files with something called a Sound Switch command class.
yes it can 
I have one on my desk actually for testing. Thank you Zooz!
You can load MP3 files onto the unit so they are stored local on the unit and then if your Z-Wave controller supports the Sound Switch Class then you can choose which sound to play and it will play them. It's actually a nice siren and it's VERY LOUD.
Just a clarification on the file format, you actually need to convert your mp3's to wav... I know And you need a Windows computer to manage the file library. That was apparently the only way to make it work and keep the library open to the user.
I'm not sure I understand the restriction or who imposed it? But thanks for the clarification I'll make a note of it as well for ISY.
The zooz siren plays mp3s at a fairly low volume. Which renders it useless for all but sirens
Download the Hubitat app
