I occasionally bump into audio with ‘whisper and explosions’, namely podcasts and audiobooks—and need to do range compression to listen more comfortably. I can do that with a variety of apps that decode the files, apply the effect and encode again into some format. However, since the source files are often shipped in the MP3 format, and MP3Gain can change volume of MP3 files without recompressing the data (just changing the volume value specified in each frame), perhaps it's possible to do the same between MP3 frames, to achieve range compression? Just for the sake of keeping what fidelity is still there, especially seeing as podcasts and audiobooks don't have too high bitrate.
Are there programs that do range compression in this manner?
Are MP3 frames short enough to permit doing this at all?