HERE:
I just tested it and it works very well for monitoring your own
sidetone from FLdigi, CWtype or any other cw sending software
when using the BREAKAWAY PIPELINE, virtual audio cable,
as the FLdigi or CWtype 'playback' output audio device in order
to send cw audio tones over to the MUMBLE INPUT on iCW.
As you can see from the attached picture,
...just select PIPELINE 1 for input and your SOUND CARD as the output...
...click on the "Source" button to activate SOUNDTAP, and then you will be able to hear your own sidetone.
It also has a nice volume slider so you can adjust your sidetone monitoring volume to your preference...
This volume slider does not affect the amount of signal that is transmitted over to the MUMBLE INPUT,
it only affects how loud you hear your own sidetone on your sound card.
This tiny program is very efficient, super easy to use, and has great audio quality with low latency.
Many thanks to SM5VXC for his design !
and to K3PGP for hosting the SOUNDTAP.exe file on his website for download.