trouble with direction of sounds in game

[lebron23]

hi everyone. hl2 is the first game i've played on a pc, so i'm definately a noob. my problem is that as i center my view on an object making noise(helicopter, tv, person talking) , the sound gets quiter. and when i turn away, the sound gets louder. if i center my view right on a person talking, i can't hear them at all. somehow the volume is reversed. i have an nvidia geforce 6200 with 128 mb ddr, an amd sempron processor 1808 mhz, and a realtek ac 97 sound card that came with the computer.

i have the latest drivers from nvidia, and for the sound card. if anyone has any advise i would really appreciate it. thanks in advance!

[Beerdude26]

snd_digitalsurround 1 or something. Type that in your console. (The console should automatically give suggestions for the correct command if you type the first few letters.)
Also, what sound card do you have?