One thing I really hate, when listening to podcasts, is people or items coming through at different volumes levels; especially in interviews. Enter the Levelator from GigaVox. A free (for non-commercial use) utility that analyses the levels across the audio stream, building a “loudness map” and leveling the volume over multiple passes. I heard of it on a podcast, which was recorded on a stage and even before it was mentioned I had noticed how consistent the level was.
Feeds et al.