Uncompressing avi? You can save as uncompressed avi in Virtualdub, but the files will be huge.

To correct your audio, you can demux with Virtualdub, which is a free avi editing program. Open the avi with Vdub, go to the audio menu and select both avi audio and direct stream copy. Go to the File menu and save as wav.

This will give you a separate .wav audio file where you can adjust the sample rate. You can do this with Besweet gui, or Audacity I believe. Both are free programs.
Use this for your audio stream when you import to Premiere, or you can remux with Vdub beforehand if you prefer.

What are the specs on your current audio? Do you know what it needs to be changed to? 44100Hz is normal for most cds, mpeg1, mp3s etc. 48000Hz is necessary for dvd audio.