Could it be that they feel uncomfortable with the fact that you are hearing impaired, and maybe they feel awkward in pursuing a conversation??? Some people do act "differently" when they know that there is something different from themselves. Are these people friendly with each other, and just single you out? I would certainly hope that this isn't the case, but people can act strange in some situations, tho I fail to see why this should happen to you - kind of like schoolkids who we know can be cruel in certain situations...

BTW - I'd chat up a storm with you anytime if I had the opportunity. Just hang in there and keep looking for that full time job that's suited just for you. It's out there somewhere.....