[DBMandrake]

Unfortunately my R-Pi (with a recent OpenELEC Helix build) isn't hooked up to my amp and I'm only getting white noise from the Pi (tested paplayer, dvdplayer and omxplayer) when connected to the stereo speakers of my monitor.

That would be expected - if you're outputting analogue audio you'd only get noise, and if you're sending HDMI audio to the monitor but it doesn't support DTS decoding it can only decode it as PCM and also give noise. (or silence)

Unless the player could be modified to heuristically check for the presence of DTS encoding with a PCM stream and switch modes so that it passes it through bit perfect (to a DTS capable receiver) or decodes it in software. Should be possible in theory, but might be a lot of work for what is still a hack.