I used to have a motherboard with Realtek HD Audio drivers. Although the driver and bundled software were clunky, annoying, and redundant, surprisingly it had features for Noise Suppression and Echo Cancellation when using microphones.
I have been taking this for granted as I work in data centers throughout the week, and I need to make calls over skype/google. Unfortunately the receiving end hears the blasting noise of air conditioners in the background.
I later switched to a computer that uses VIA drivers, also with a bundle of clunky drivers. Unfortunately, they don't have any of these features.
So I've been looking hard, but can't find any software that can perform the noise cancellation. It seems like it would need to hook in the driver level, but maybe this can be a generic filter that is used by applications that need to interface with the microphone.
Any information would be useful.