How to import two sound into one slide show

Hello again
You know,it's my habit to have a background lite music in my powerpoint presentations
I chose a wma sound for the first slide and I tick "loop until next sound".With this method the music will be imported INTO the slide show and it will play the sound no matter where the sound file is(let me explain more.If I INSERT a music file,using the insert tab,powerpoint will go to e.g f:\music and play track1.but if I move this slide show to my friends pc,the music file won't be played;because there is no f:\music in my friends pc.
hope you got it)
Now I want to import a background music(as usual) AND my own voice,recorded lately,which is another wma file.

So how should I do it?
Is it POSSIBLE?
thanks