Slim,
keep up with all fluids no matter what!! Even through the Tube if that will help, but do make sure you swallow as well daily. Eating takes time and he will slowly improve. Be sure to search the site for easy foods to eat.
Do not be so eager to get rid of feeding tube, it is a very important for his recovery. I did not get mine out until 9 mo.
He will slowly improve..about 3 mo. he should see a small improvement and then again at 6 mo. His body has been through a lot. It needs time to heal. High protein will help in healing along with rest.
Hearing loss, may improve in time. How much is hard to say, that takes time too.
Take care... Diane