Skyrim Special Edition may feature improved visuals, but sharp-eared players have been noticing a significant drop in audio fidelity. Redditor LasurArkinshade posted an explanation as to why the audio in the Special Edition sounds less crisp than the original Skyrim, and it's apparently due to how Bethesda has handled it sound assets:
"The vanilla game has sound assets (other than music and voiceover) in uncompressed .wav format," the post states. "The Special Edition has the sound assets all in (very aggressively compressed) .xwm format, which is a compressed sound format designed for games. This isn't so bad, necessarily—it's possible to compress audio to .xwm without significant quality degradation unless you crank the compression way up to insane levels."
"What did Bethesda do?" the post continues. "They cranked the compression way up to insane levels."
Below, you can listen for yourself using LasurArkinshade's comparison of the level-up sound, first from the original game, then from the Special Edition.
I didn't really notice much of a difference through my speakers, but even putting in my ancient earbuds I could definitely detect a severe downgrade in audio quality. It's even more apparent with a proper gaming headset.
Why decide to package the audio this way? We're not sure, but it could have something to do with minimizing the size of the Special Edition download. I've sent an email over to Bethesda and I'll let you know if I hear anything back.
In the meantime, Reddit apparently already has a way to fix it: by zipping up the audio files from the original and importing them into the Special Edition. User TI36X reports: "I extracted my original Skyrim Sounds.bsa, packed it with 7zip and installed it with NMM in SSE. Seems to work fine."
"There are two folders in the bsa," says TI36X. "Sound and Music. Just pack them into a archive and install by NMM [Nexus Mod Manager]. Someone just uploaded a bsa extractor on the SSE nexus that works for this."
The bsa extractor in question is here, though I should point out I haven't tried this process myself, so extract, zip, and install these files at your own risk (though these are just sound files, and you can always just reinstall the games if it messes something up, so there's really very little risk).
