I have a camera which introduces some high pitched whine into the audio. I would like to keep using the camera and edit the audio with a low pass filter.

Using Vegas Movie Studio, I see that there is an option to open audio in the audio editor but I find that there is no audio editor.

I tried specifying Audacity as the editor but it could not cope with the audio format.

Do I have to buy Sound Forge (or rather its cheaper version) as well?

Fxeditor seems to be cheaper and adequate for my purposes at 40 USD.
http://fxaudioeditor.com/series_4_order.htm
Goldwave may well deal with ADPCM too at 50 CAD.
http://goldwave.ca/forums/viewtopic.php?t=420
Sound Forge Audio Studio at 70 USD
http://www.sonymediasoftware.com/pro...orgefamily.asp

Are there any free solutions?

The audio that I want to edit is "IMA ADPCM" apparently. I don't know what that means. I don't even know if Sound forge will deal with it. Will it?

I could render the audio chanel as mp3 or ogg, edit it with Audacity and then reimport to Vegas but that sounds a bit longwinded.

Your suggestions will be gratefully recieved.