Update...

So, I just got some more information on my dad. Apparently, the only way to diagnose a leak in the inner ear is by doing surgery. So, he is going to his regular doctor to have a full physical and they will check all his levels and things to make sure nothing crazy is going on. If everything is normal then he will go back to the ear, nose and throat doctor and they will discuss surgery. They don't want to do surgery until after they check everything else out. As far as I know he will remain out of work.