Using Speaker Companion, with a Sonos One, I have it set to “Temporarily increase volume”, but the increase is not temporary. The volume will be at that same increase when I play music.
I’ve been looking for this feature since I first got into Smartthings. I had kept my Honeywell alarm in place to simply play “beep beep beep, the front door opened” and similar sounds for other doors and windows. With the Sonos wifi speaker I can do this and more, love it. My only issue is that the volume level stays at the temporarily increase level, so when play music later I have to immediately turn the volume down.