Volume too low for those of us with bad hearing

I know of no way to directly get more volume from the iPad. However, many amplified headphones are available. Just Google for:
amplified earphones ipod

Yes I know where your coming from ,I purchased a set of in ear head pphones buds sure se 210e and they cut most of the background noise on a plane making music more pleasurable and I found the volume was just right for me,I also have the apple ear buds with the remote also work very well maybe not as good as the sures but very good at cancelling background noise ,they also have a problem sitting next to the wife as I can't hear her talking and I get the dunt in the shoulder every time she speaks and I don't answer usually this happens when your into a good track but that's the price you pay I guess. For being married. or having a good set of ear buds lol

I am hard of hearing, to the point that I use hearing aids. When I travel on planes, I don't use the hearing aids so that I can use my Apple earphones.

I recently returned from a trip during which I used my iPad to view 4 movies and listen to the iPod app during the long flights. I never have to turn the volume up to more than 3/4 of the way. My older iPod, my 3GS iPhone and my iPad all have similar volume levels. If I turn them up all the way, it is far too loud.

You didn't say if you had already checked the volume settings in the "Settings" app. Just to iterate, go to settings, general, sounds and make sure the volume is set all the way up. Then in settings select "iPod", volume limit, if it is on you can turn it off and slide the volume all the way up.

Doing this will allow you to adjust the volume on the iPad as needed based on what you are listening to at any given time.

If none of this works for you, I would have the iPad checked out.