Distorted MP3 Audacity 2.2.2

I’m new to Audacity and need a bit of help.

I have a 2hr recording in MP3 format. The recording plays fine in media player classic which is part of the K-Lite codec pack

The recording loads fine into Audacity but generally sounds a bit muffled. A couple of sections are distinctly distorted.

Clearly I’m missing something important and I’d be grateful if somebody could point me in the right direction

Many thanks


That shouldn’t happen… You can get differences when you compress (encode) MP3, but decompression (decoding) should always be the same.

You may have some equalization or other effects applied in your media player. (Audacity does not apply effects in real-time).

Of course, I’m assuming that you are listen to the same computer/soundcard and the same speakers/headphones at the same volume, so the only difference is the software?

Thanks for your comments. To be clear

If I play the recording through a decent set of speakers on another computer using either Windows media player or media player classic the recording sounds just fine.

If I switch to a much more powerful computer with reasonable speakers attached that I use for editing and play the recording through media player classic it sounds exactly as I would expect.

If I then load the recording into Audacity and play the recording it is distinctly muffled over just about all the recording and unpleasantly distorted over a few sections. I’ve clearly got something wrong in using Audacity but I can’t find what it is and I would appreciate any guidance that exists on ensuring the MP3 profile in Audacity is set up correctly.


I have a 2hr recording in MP3 format.

Who made the recording? If you, what were the MP3 parameters? Bit rate?

If somebody else, how do you know it is an MP3? Windows likes to hide info like that.

That shouldn’t happen…

Right. That’s impossible, so what it looks like is happening and what’s actually happening are different.

Audacity doesn’t edit MP3. What it does is import the sound and convert it to a super high quality WAV format so editing, effects, filters, conversions and corrections can’t damage it. Then it makes a new MP3 or whatever else you want when you export. That’s why you can never export an MP3 in the same quality that you imported it, and that’s why you should never use MP3 as edit material or archive.

That’s also, by the way, why the editing process can have surprises along the way. Your adorable little sound file in MP3 (pinching cheek) balloons into larger than 2.5GB monster inside Audacity. Audacity makes complete copies of the file each edit and that’s how it does UNDO. It just plays back old timelines at 2.5GB a pop.

One troubleshooting technique is do something wacky. What happens if you play the sound file in Audacity on the first computer? I note that’s one step missing in this process.

Select some of the distorted and muffled work, Export Selected > WAV (Microsoft) 16-bit and play it on the original computer. If you make a 10 second WAV you can post it on the forum. 20 seconds if it’s mono.



Oh, wait. One more. You could have a Sound File From Hell. If you have a sound file where the Left and Right tracks are recorded out of phase, it’s terrifically hard to sort what happened while you’re listening in stereo—two track, two speakers, etc. But the instant you listen in mono-mix, all sorts of nasty things happen including having the show vanish. It could certainly account for muffled sound and distortion—only under certain conditions.

Is it a stereo track—two blue waves? Use the left-hand menu system > Split Stereo Track. Select one track of the split by clicking just right of the up arrow and Effect > Invert. Menu of the top track > Make stereo track.

Problem gone?

If it is, we should track this back to the maker and find out what’s causing it. This isn’t an Audacity problem other than it may be configured to reveal the error. There are perfectly innocent-looking microphone adapters which can do this.


Of course, it’s also a given you’re listening in mono, not stereo. So that could be a surprise. This could happen if you’re listening via a very fancy gaming system that likes to “improve the sound to help you.”