I had a look at Sony's audio studio and at Goldwave, and found the latter to be preferable.

The sony interface is nicer and the show me how is still there (with audio I am not sure I need to be shown how) but Goldwave seems to have more features.

I am going to have to ask on the forums but I could not find a way of removing noise *using a sample of the noise* using Sony's product. It had a automatic noise removal tool which removed my voice as well. Goldwave on the other hand allows you to copy a bit of the audio which is all noise (where there is no speech) to the clipboard, and use the contents of the clipboard as a basis for 'that which must be removed.' Audacity's sound removing tool also allows one to select some noise.

I did not see a low pass fillter in teh sony product - only an envelope (perhaps the same thing in effect) and a graphic equaliser.

Tim