[Elecraft] KX3 - Splitting receive audio between PC and external speaker?

[Mike Parkes]

I am interested in determining the best way to split out the KX3's receive
audio for digital modes to an external speaker, so that if I want, I can
listen to the band while running digital sound card modes. (Maybe I am just
too old school, but my older rigs (like the IC-751a) could do this easily
because they had a separate digital output for rtty and other fsk modes. So
I was able to monitor the band while also decoding digital modes.) I
thought I could use a splitter from the KX3 phones jack, and send one side
to the PC and the other to a speaker (with its own vol control). I have no
idea how that will impact the signal going to the PC though, at the least
it will be less level to the PC. Or perhaps one of the USB sound card
interfaces can do this, as I think some of them have their own audio out?
Ideally I would also like to be able to monitor the transmitted audio
signal too if possible (whatever the signal is that is leaving the PC and
going to the KX3. If anyone has any advice on this I am all ears.
Thanks!
Mike AB7RU