Is there a circuit simulation software with actual audio input/output ability?

[jimosity]

Basically, what I'm wondering is if there's a software where I can take say a clean guitar signal, use it as a loop - have it be used as the input to a circuit, then hear the output of the loop at the same time, then move/change parts around to HEAR the changes in real time?
Sorry if this is a dumb question.

[CynicalMan]

Yep,

 

Seriously, any circuit simulator is going to be too complex to do in in realtime. You simply cannot have a simulator that's accurate enough to simulate most circuits and fast enough to have realtime output. LTSpice has a very slow wave in/out, but that's as good as you're going to get.

[toneman]

Linear's PSpice can create waveforms that U can hear. 
MarkusW did it with the RingStinger, I think(?)
He created modulation waveforms and fundamental for the ring modulator.
I'm sure there's someone else that knows how to get "sound" out of PSpice(?)
Not me, though   
afn
 

[diydave]

With Ltspice you can feed your circuit a wav-file of what you've recorded.
The output is also wav.

The user-manual explains how it's done. Quite simple.

Done it a few times, with interesting results.

[Cjuried]

This might be of interest... http://www.livespice.org/ I am starting to dig into this a bit further. Has anyone found other options? Thanks!