It appears that pretty much every game out there implements stereo for speakers: that is, if a sound comes from the left, only the left speaker plays it. There is none of the sound coming from the right speaker at all.
Unfortunately this doesn't work very well in headphones at all. When something makes a noise on the left, both of my ears hear it. The right one is only slightly quieter. What's really important is the time difference between the left ear and the right ear receiving the sound.
I always play games in headphones, and to me the sound of speaker stereo through headphones is very unpleasant. In real life, you just never ever hear sounds with just one ear, but in modern 3D games I get that all the time.
Is there some way I can fix this in games that don't have explicit support for this? Can I install some software that does this, or buy an audio card that applies the necessary changes in hardware?
(I'm on Windows 7)