Unless I'm mistaken, you should be able to hear the sounds you're playing on the Orba 2 on an attached computer, correct? Nothing comes through at all for me. I'm connected successfully, and the settings in the desktop app seem to work (toggling "Orba Sounds with USB" disables the local sound on the Orba 2), but no sound ever comes through the computer. Pressing the "Test" button next to the audio device output does indeed play a tone which I can hear just fine on the PC, but that's it - no other sounds seem to work. Is this a known issue? Device firmware is up to date.
Both Orba and Orba 2 function as MIDI controllers when connected to other apps, but do not transfer any of the internal sounds via USB to the computer.
As Britt from Artiphon said, The Orbas are currently, and perhaps forever (?), only MIDI controllers. That means that they send MIDI information - "key" presses, "events," but not sounds. They are not currently sound or tone "generators" for that can receive MIDI data from other controllers. That still makes them a very cool way to control other synths, especially MIDI over Bluetooth synths. It also gives you a way to record your songs, although not with the built-in sounds. You can essentially record .MID files and reassign the parts to any instruments you want.