F37 XFCE bell – where to turn it off

[Sam Varshavchik]

After updating to F37, the new XFCE desktop appears to have implemented the  
screen beep/bell function. The default beep/bell audio is quite annoying,  
does anyone know where the setting for that is, I can't find it.

I tried doing

xset b off

But it's still barking at me.