I have a condenser mic, with phantom power and the vocals are only coming out of one headphone on Ipod but on both headphones on media players on desktop. My set-up is Audio Host (MME), Playback: Microphone (Fast track), Recording: Microphone (Fast track) on stereo input. The Wav file vocal comes out of both headphones on Itunes player and when uploaded to youtube. But when I put it on my Ipod or on my friends phone the vocal comes through only on one headphone but the track is coming through both ears. I tried converting the Wav file to Mp3 and put it on Ipod and phone and still the same result, vocals only coming out of one headphone. Thanx for any help in advance 
Single microphones generally record as a single mono audio track. You can force the system to create a “stereo” or dual channel show by duplicating the single track so you have two independent versions of the same voice and then “marrying” them into a stereo show. I tend to like that because then it’s not ambiguous when you start to mix into other tracks most of which are going to be full stereo, it’s what many of our clients are expecting, and I don’t get problems like you have.
So I think you have a stereo show with voice on the left. If you play that show on a mono system, the voice will seem to play just fine with the music – both headphones, but if you listen on a good stereo system, the voice will drift to the left which is where you really put it.
This is a post production adjustment. I don’t think you can do anything with the tracks you have now, unless you saved your show as an Audacity Project. Projects retain the channels as you recorded them and you can remix them as you wish. You can’t remix the MP3.
You can load the show you have (I’m assuming MP3) and mix it down to mono in Audacity. Tracks > Stereo Tracks to Mono, and then export that. The problem with that is you can’t make an MP3 from an MP3. The compression damage goes up and the show will start to honk and gargle at you. Never do production in MP3.
Koz