I like to experiment with this vocoder atm. It's very interesting to process various sources, not only human voices. So more sonic examples will -hopefully- come.
As a starting point, to pitch a human voice, and in Cubase (but even if the workflow is similar in other daws, you'll have to adapt it)
1/ Record the original voice on an audio track (prefer. mono) if you don't already have recorded vocals.
2/ In Cubase Mixer, insert the X201 as a VST effect. You can consider to add a compressor before the Vocoder if the vocal track level is not very consistant.
3/ After you have inserted the X201 vocoder, you'll get no sound. Don't worry and see next step.
4/ Create a new MIDI track in Cubase. In the inspector panel, set the Midi routing : Midi Output of the Midi track to the Midi INPUT of the X201 (X201 will appear in the list)
5/ Now just play a melodic line on your midi KB, or chords, in sync with the vocal -audio- part and you will 'sing' it
So, it just requires a few seconds and a few clicks, but this has to be done in a precise order.
You can 'see' an example of all this in my 'Daft punk' Video. I used one Midi track for the main melody. A second one to add a bit of harmony. And finally a third one to automate the Delay Volume, which I assigned to mod wheel in the mod matrix for this patch. https://youtu.be/I9modOKZdRM
Hope it helps.