Totally agree re: headphones. As for soundcards, last time I checked (admittedly, in 2008) the popular audio APIs did not support software HRTF-based 3D audio. In uni, I worked on an audio based augmented reality project[1] using FMOD for audio and the software-mode did not cut it (3D was not very easily localized) while using hardware mode with a X-Fi soundcard (the ones with hardware HRTF - the Xtreme Audio did not support it, despite advertising CMSS-3D) had pretty good results. Perhaps FMOD (and OpenAL) have got better software 3D support now. I do agree that we now have the processing power that HRTF could be done in software (and afaik adding the functionality to FMOD through effects plugins should be possible), but I don't know if anything exists yet - at least, it didn't back in 2008. [1] http://dublindan.posterous.com/things-ive-worked-on-1