The Levelator at Mac App Store analyse

The Levelator is software that evens out the variations in audio levels within your podcast or other audio file. For example, so one speaker is at the same level as a second speaker. It's not a compressor, normalizer or limiter although it contains all three. It's much more than those tools, and it's much simpler to use. The UI is dirt-simple: drag-and-drop any WAV or AIFF file onto The Levelator's application window, and a few moments later you'll have a new version which just sounds better.