There are websites that sell alarm clocks, as well as smoke detectors, baby monitors, doorbell alarms, you name it for the deaf and hard of hearing. If you check out the website for the League for the Deaf and Hard of Hearing, they may have a link on there. They have some that come with a vibrating bed shaker that goes under your pillow, others that have strobe lights and some that hook directly up to a lamp in the room.
I was recently looking for that type of baby monitor. My husband is in the Navy and once we transfer back to Virginia he will be out to sea for about 6 months, so I won't be able to rely on him to hear if the baby wakes up. As far as the alarm clock goes, I have a 5 year old who makes a very effective one. I just entered something like 'alarm clock for the deaf" as a search on my computer and came up with a bunch of places to chose from, and the prices aren't that bad. Also, a medical supply store may be able to order them for you.
Good luck to your son on Monday. i will keep him and the rest of your family in my thoughts. I hope Santa brings you all something nice this Christmas. Sounds like you could use a nice getaway to spa or something - good heavens - 6 kids!
Please keep us posted on his progress.
Lori