I really need help with this guys.Every time some non human creatures come near me the game starts to lag HORRIBLY.I found that the problem is the integrated sound.Overall the performance is good and smooth and despite the lagging issue i haven't any CTDs.I don't understand why some people with integrated sound cards like my friend doesn't have any problems but i have.I want to note that this problem is relate ONLY with Oblivion.F3 and New Vegas are perfect.

Thing i tried:
Quietfeet mod - works but only for the main game not Shivering Isles plus i wan't to hear the steps.
Setting Audio Acceleration to "emulated" - again works but the sound is really awkward o.O
Disabling ALL sound in Oblivion.ini - guess thats not a solution.

Also should mention that I have K-lite codec pack.Is there any way to use it as tweak?My sound is VIA HD 1708b on nforce MB.And why my friend can run and i can't it.This makes me go RAGE.

Turn off music. That was a big performance gain for me.... (on a P4 machine...)

It's not the music it's turned off already.It's the footsteps.Am running the game MAXED OUT on 1440X900 at 60fps i don't need more performance.

Provide specifications on hardware...specifically CPU, RAM, and GPU. You've tried pretty much all the necessary means to determine whether or not it was the onboard sound caused the issues....and yes, onboard audio is hit-or-miss with many players in this game. Some have issues, others don't.

At this point, I wonder if it's your CPU just simply not being strong enough that it's causing you the lags.

My CPU is Intel core i5 at 4GHz.Um video GTX560 RAM 8gb.And pretty much excellent HDD which is defragmented.But no need to help me anymore guys thanks.I guess i have to start to save money for sound card.

Is your friends machine also using the VIA chipset and the same drivers that your system uses ?? -- the problem is usually specific to certain audio chips and the drivers available for those specific chipsets -- try updating the driver for your VIA chipset if you can find any.