Using MP4a in PSE 12.

Using PSE12.  I am trying to load audio into a slide show.  MP4a is not listed as an audio option.  Elements will not recognize iTunes audio.  iTunes says it is AAC. Copying the audio from iTunes says it is NOW MP4a.  I have PSE14, but it has a crappy slideshow,  However, PSE 14 does recognize MP4a audio.