Computer's default input device will be the USB headset (so you can talk through VoIP).

This is recording software, but we are just going to use it to route the audio coming from your piano (through that interface I mentioned earlier) to your computer's output (your new USB headset). You will need a free open source program called Audacity. Any USB headset should work for this, just make sure there are Linux drivers available if needed. Okay, so that's all great, but if you want to use a headset, our solution is going to change, and we will need to use software to do it, especially if you are using Linux (I think that's what you're indicating?). Now you can hear your piano audio and computer audio through the same headphone output. This next part may be difficult to answer, simply because I don't know how your wireless headset connects to your computer (USB? 1/8' jack? Bluetooth?) Ideally, you would just plug regular headphones into the headphone jack of your new interface, and select the interface as your computer's audio out. Now all you have to do is select the interface as your audio input. The piano will connect to it using an RCA connection (my piano only has 1/4' outputs, so I picked up 1/4' to RCA converter cables). I have the same one which I found at a local music store for around $30 CAD. Here's a link for a very basic one that's also pretty easy on the wallet: First of all, we need to get audio running from your digital piano into the computer.

Piano keyboard connect to computer