Im using a Mac OS X 10.8.3 and Audacity 2.0.3 . My mission is to export a good quality MP3 music with voice file from audacity into i tunes. So I exported it as an MP3 file and dragged it into my i tunes folder…but when I played it back the 2nd half didnt play… When I exported it as an AIFF file into i tunes… it played perfectly…but when I right clicked on that AIFF file and clicked create an MP3 version …I couldnt find where that MP3 version is…
Could anyone please tell me what Im doing wrong? 1st I thought I could export as MP3 file thanks… 
All MP3 files throw away quality. The higher the bit rate, the less quality is lost.
You need LAME ( Audacity Manual ) to export as MP3 from Audacity.
If you still have the Audacity project, look at what you did. Perhaps you only selected the first half then did File > Export Selection. Perhaps the second half was on its own track and you muted that track. Muted tracks are not exported.
If you are trying to play the file on an iPod, try connecting the USB cable to it so that it has mains power.
If iTunes converted the AIFF to MP3, right-click over the converted MP3 and choose Get Info.
Gale
Hi Gale…thanks for your reply…I thought the LAME download was only needed in the past to export audacity files and now an upgrade in audacity means thats not needed anymore ? thats what Ive read ??? 
Tell us where you read that.
You need lame to export an MP3 and FFMpeg to manage advanced compressed audio file formats.
Koz
Ok Koz… thanks for that… Ive got around it by exporting as an aiff file and then converting to mp3 in i tunes…