It appears that the Mac System Volume (e.g. Internal Speaker Volume for the entire Mac) is being changed to maximum when starting Dorico or sometimes when switching back to Dorico from a different app.
It seems to me that Dorico should be free to set its own app volume (whatever goes to the System Sound Mixer) but should not be changing the Mac’s or other audio device’s output level.
This can be quite painful and possibly dangerous if using headphones, and quite annoying to the family otherwise.
If there is a workaround, I’d love to hear it, and if not, I’d hope to see if fixed in the next release.
Dorico Pro 188.8.131.522 (Feb 17 2020)
MacBook Pro 2016 - 15" Mojave Version 10.14.3