Sound Problem

HelloFirst time posting in this forum, but i've been reading it for a while. I'm not new to FSX, I started doing flight simulation by FS 2000, and one year ago I bought FSX. I don't have any problems with graphics, I think they are very good for my specs, I will show them later, but I always had this problem with Engines Sound: when they spool up, i.e. throttle increasing, their sound does not goes up smoothly, instead they go up like steps. Or another explanation that maybe a tad more clear, 10% is throttle close, and 100% full throttle. When applying full throttle the sound does not go like 10%-11%-(...)-98%-99%-100%, but 10%-25%-50%-75%-100%...I hope I'm clear, but English is not my mother tongue, and the problem us hard to describe. Thank you very much for any input you can give...bohemianboySpecs: Laptop Sony Vaio FE21mIntel Core Duo T23001GB RAM 160 Hard DrivenVidea GeForce Go 7600Sound must be onboard...