The trick to hearing PowerSDR audio in/out during digital mode operation ...
If you have diverted PowerSDR inputs and outputs to stream audio to and from a digital mode program, then you no longer hear the receiver output, like you found. There are several ways of hearing these signals again. One way is to use Virtual Audio Cables'
Repeater application - you can start as many of them as you need. All a Repeater does is link an audio input to an audio output. In your case, use a Repeater to link one of the audio cable lines to your speaker output, to hear that signal again.
See here for more explanation. If you also wanted to hear the other audio cable line, start another Repeater and link the other audio cableline to the speaker output. Notice Windows will mix these toegther quite happily, so you can hear both receiver and transmit signals.
Regards, Bob G4BBY