We need more more info for a detailed answer but the basic reply is "Yes".
You will need a microphone and some form of audio interface (to plug the mic into the computer--built in sound cards and the included jacks are often not suitable for anything more than a gamer's mic).
Export your Premiere Pro Project (Edit/Edit in Audition). This'll take your video and existing audio across to Audition.
Create a new track in Multitrack View, enable that for recording, route your mic/interface to that track then play the existing stuff to watch/listen to while your record your comments.
When done you can either mix it in Audition or send all the stems back to Premier Pro--I usually mix in Audition but that's just because I now it better.
I realise this is a very simplistic summary but you'll need to read up (or watch training videos) to get all the details.