audacity plays mp3 file at 500x normal speed

Using Audacity 2.3.2, Win7 64bit.
I just opened an mp3 file in audacity to do some editing. the file plays fine in various media players. but audacity plays it at over 500x normal speed. a 26-minute mp3 plays in a bit over 2 seconds. sounds like birds chirping. the wave graphic is very compressed visually and both bass and treble are severely clipped. when I zoom in on it, it’s rendered as a series of vertical lines of varying length, each with a small ball on the tip (top or bottom depending on the direction of the vertical line - see attached image). If I re-export the file as mp3, it ends up as a 2-second file of chirping sounds.
This has never happened before. Any suggestions?
Thanks in advance for any help!

Any suggestions?

Since Audacity plays MP3s, it’s not an MP3. You can find out what it really is…


Thanks for the link!
This is odd - the link you provided says it’s AAC, but if I right-click on the file and look at “properties” it says “MP3 audio file.”
Obviously there is a problem with this file. It was supposedly converted from AAC to MP3.
The original AAC file functions perfectly on Audacity (thanks to FFmpeg).
So if the supposed MP3 file were really AAC, it should also function on Audacity and it does not.
There must have been a problem during conversion.

Right. So that’s just broken.


Luckily I still have the original AAC file.
I’m gonna keep the corrupted one - it will make an interesting ring tone, and the wave form could become abstract art, or the score for a robotic concerto. :smiley:

As you’re finding out, the file header, all that information at the beginning of the file can be different from the actual data. If you find two different methods of measuring the file and they say different things, chances are good that one is just looking at the header and one is analyzing the actual data.

The file name can be different from both.

Complicate that with computers insane desire to hid filename extensions. Count the number of “MP3” files on the forum that turn out, on careful inspection, to really be MyMusic.m4a or something else. Hiding the extensions can be handy, convenient, and pretty, but it falls apart pretty quickly when something goes wrong.


What I find interesting is this: the (apparently corrupted) file still plays just fine on Windows Media Player, Pot Player and other players/editors. Audacity seems to be an unusual exception. So the problem seems to be specific to Audacity.

Have you tried re-naming the file AAC? Audacity can open MP3s without FFmpeg so it’s probably not even trying to use FFmpeg.

audacity plays mp3 file at 500x normal speed

:smiley: “Ludicrous speed” if you ever saw the movie Spaceballs! :smiley:

Light Speed is too slow…