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My company works with audio recordings of phone conferences. We record those as WAV then convert them to MP3 for storage. The stored MP3 files are the ones users globally can download.

The problem is, that conversion from WAV to MP3 introduces audible artifacts. Whereas the WAV file was quiet, the MP3 file now has background hiss. Sometimes, the MP3 file even muffles audio from lower-pitched speakers. It's bad.

I've read good things about Opus, but I'm not sure how playable it is for everyone. Compatibility is important since we want to avoid issues with users not being to play the audio.

What's a better lossy format than MP3 for speech audio in terms of quality and compatibility?

This question has been asked here before, but it was back in '11. The answer then was still MP3, but I wasn't sure if I can just edit someone else's question from long ago.

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The best solution for this longer term is to use the Opus codec. There isn't anything better in terms of speech/music compatibility and also bitrate flexibility. Compared with mp3 it is a fairly new codec, but support for the codec is growing rapidly and most browsers have support built-in to allow you to play back Opus encoded data from within the browser.

  • Yeah. Using Opus would definitely improve quality. I think it makes sense that modern web browsers already support it, but we also allow our users to download the file. I'm just really afraid of some normal user downloading a .opus file and not knowing what to do with it. Is it popular enough format to play on every default media player of any OS out of the box? I wonder if it's already dummy-proof. – kelvinilla Apr 14 at 14:01
  • This all depends on whether you want to settle on an archive quality lossy codec - like opus, or whether you can afford the storage to use a lossless format. With speech, another option worth considering is to degrade the original recording down to 32kHz and 8 bit resolution mono. This would allow substantial data rate reduction without significant quality loss. Addition of dither can also help with this process. – Mark Apr 14 at 14:19
  • I might try lowering the resolution of the WAV then since that still plays in as many places as MP3. I really hoped I was just missing out on Opus, that it was already everywhere but I haven't noticed. Thanks. – kelvinilla Apr 14 at 23:37

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