Peter wrote in
:
Is this true if one is using an intercom which has TWO buttons for
idents; one marked DME and the other marked NAV?

Yes. If you listen to both simultaneously that's what you will hear. If
you only listen to one, then you'll only hear the one you're monitoring.

I don't understand how a DME ident can be (as a general rule)
incorporated into the VOR signal.

It isn't. It's on a separate frequency, but paired to the associated VOR
frequency. But it's easy to combine both signals through one switch,
thus saving a little money on the unit, and some prefer to hear both. I
prefer having separate monitor switches, but you can combine as many
signals as you like into one switch.

--
Regards,

Stan