Summary: Great discussion with Allan Tépper. He is the host of Beyond Podcasting. *DISCLAIMER: We are not advocating for anyone to switch from MP3 to AAC (.m4a). If you're contemplating it, please do more research and decide for yourself. We discussed many aspects of MP3 vs. AAC (.m4a). The widespread reluctance to even THINK about publishing podcast episodes in any other format than MP3. Sound quality: AAC sounds better than MP3 especially when encoded at lower bitrates.