Using Audacity to slow mp3s

I have been successful using Audacity to slow down mp3 files that I find in various sources…until I tried it with radio podcasts . The files as I download them are mp3, but when I import them to Audacity to edit, they are not usable as is. Does anyone have experience with this ? I want to augment my auditory input, and many of the programs are very interesting to me, but too fast ! I love Audacity, because you can choose what percentage speed or tempo to change.

I use audacity to cut out the not so useful vocab from the FSI and DLI courses.

“The files as I download them are mp3, but when I import them to Audacity to edit, they are not usable as is. Does anyone have experience with this ?”

I have never had a problem importing any type of mp3, so I don’t know what could be the problem.

this is my first time with this problem. I thought an mp3 was an mp3 was an mp3 !

Maybe importing the file into i-tunes (creating another mp3) and then putting the new file into Audacity might work?

What I meant was any piece of audio in mp3 format. There is only one mp3 format, so don’t worry about trying to figure out the different types of mp3. :slight_smile:

I just tried it and same problem. Instead of the file showing up as 1 hour 35 minutes long, it shows up as 3 hours 15 min. long and sounds like machine gunfire. I only have basic experience using Audacity…don’t know if I can change the size of the file…

You might be making the audio go too slow then. This is one of my guesses. Slower you make the original audio, the longer it will be. Or are you sliding the tempo settings a bit too far to the left?

I don’t even get to the point of doing any editing because how it comes in to the program is screwed up (sorry for the lack of technical lingo! I don’t have the vocabulary in any language to describe this). Well, maybe I should start with simply trying to change tempo or speed and see what happens

You could try creating a lesson here, uploading it and listening slower via LingQ. See if LingQ will process it and recognise it.

You may require the lame mp3 encoder. It is a .dll file that Audacity needs to reference for proper encoding.

Check Audacity setup. Go to Edit → Preferences → Libraries. Check to see that you have a valid mp3 Export Library referenced.

That would be a work-around but Audacity gives options to slow the tempo or pitch or both at once. The slow option here on LingQ leaves a lot to be desired. Almost to the point it is unbearable to listen for longer than a sentence at a time.

I don’t what program it was that I was using a long time ago, but it prevented the use of .mp3 files to discourage pirating. Maybe it was Audacity.

Every file I’ve used in Audacity was an .ogg file. The problem there is, you then can’t use it on an mp3 player!

I’ve never heard of .ogg files . I edit mp3 files in audacity all the time, as I’m a folk dance instructor and work with elderly people, and have to slow down the music for them to dance to it.


I have just tried with a random podcast (on and Audacity has no problems opening the mp3 file.

Are you sure that you have downloaded the correct file, i.e., can you play the mp3 file on your computer with another program? I am asking because sometimes a webpage has a “Download” button which looks like linking to an mp3 file, but in reality it is a link to another webpage with an embedded mp3 file.

By the way, in the case you are using Windows to play the file, did you know that you can control the playback speed in Windows Mediaplayer?

I’m 1000000% sure they are mp3 files ! (I have had so many people ask me that !) I download them from the podcast page directly, and I can play them in windows, but I want to take them with me on my iPod. It works fine with short mp3 files, but some are 50 minutes plus, and they don’t load into audacity properly. This really is a fantastic practice, since with just 8% slowdown I can understand nearly 100%…boosting my enjoyment of listening immensely.

Can you send a link? Then I can try it myself.

any of the podcasts from this site:

These are over an hour long. Does that make a difference to audacity ?

Bad news: it works perfectly on my computer :slight_smile:

I have tried the podcast from May 16 (duration: 1h38’). It’s quite slow (Audacity needs around 5 minutes to load the file, slow it down and export it as mp3), but the result is flawless.

I have tested it with the latest version of Audacity 2.1.0 on Windows 7 and also with an older version 2.0.3. For exporting, I took the lame_enc.dll from here:

My version of Audacity is 1.2.4 ; maybe I need to update, although it works fine as I said for short mp3s. This is very interesting information…thank you for testing it !

There are programs to split long mp3 files for example mp3DirectCut. Maybe it helps to split them into smaller chunks before you import them into Audacity.