No audio in converted videos

Hello,

I am attempting to convert some .vob videos. I have tried multiple formats, but every converted video has no audio. I have seen a lot of discussions on this forum about similar situations, but have not managed to fix my problem. I am hoping for some advice more specific to my situation. I am using AME CC 2018. This is my first time using the program so I cannot give too much information about how it has worked for me in the past. I converted a wmv video in order to see how that would work and that converted video does have audio. That makes me think the problem might lie with the vob videos I have, but I do not know what problem that could be. Any help would be greatly appreciated!