Gallaudet University which is nearly 100% deaf and hard of hearing students. However, these students often still identify with the deaf population and want to be at schools that have a significant deaf population. This allows them to be involved in activities with other deaf students. Additionally, they can still benefit from services that tend to be offered on campus with significant hard of hearing populations, such as note-taking, oral interpreting,realtime and typewell captioning. Here are a few school ideas for your student:

Rochester Institute of Technology has the National Technical Institute for the Deaf. This has a deaf and hard of hearing student population of about 1,300 students on a campus of about 14,000.
California State at Northridge (CSUN) has the National Center on Deafness, which I believe has a deaf student population of about 220 students. The campus has about 31,000 students.
UW-Milwaukee has about 50 deaf and hard of hearing students on a campus of 24,000.

Each of these schools have an American Sign Language major and have significant populations of hearing students that also sign. For example, at UW-Milwaukee nearly 1,000 students on campus use ASL.

Don't be concerned about coming up with a list of "deaf community only schools" because I believe there is only ONE and that is Gallaudet University in Washington DC. Rochester Institute of Technology (in New York) may come in second place because they have a division for students who are hard of hearing (HOH) or deaf called the National Technical Institute for the Deaf. There may be a few other universities in the country that have a division similar to Rochester Institute of Technology.

I am not aware of any LIST of colleges that have captioning or academic support for the deaf community but I do have good news: Most colleges today are doing a pretty good job in meeting the needs of students with all kinds of disabilities.

My advice (and deliver this message to the family) is to eliminate the concern of finding schools with CART, real-time captioning, etc. because by doing so you are putting this student's disability first - not the student first. You are not working with a deaf or HOH student. You ARE working with a student who happens to be HOH or deaf. My advice is to concentrate more on the usual criteria - size, location, cost, major areas of study, sports program, Greek life, etc. THEN, after you have a list of colleges to consider, contact the disability office of each of the colleges to find out if they have closed loop FM systems, CART and other assistive technology that would be appropriate for your student. What you really need to determine is how disability-friendly are the colleges on your list. I think you will be very surprised that most colleges will fit the bill.

The University of Iowa - Student Disability Services offers the accommodations following for deaf and hard of hearing students:

http://www.uiowa.edu/~sds/deafhohaccomm.shtml

"Transition to Adulthood"

http://www.gallaudet.edu/clerc_center/information_and_resources/info_to_go/transition_to_adulthood.html

PEPNet 2

http://www.pepnet.org/

"Hard of Hearing Students in Postsecondary Settings: A Guide for Service Providers"
http://www.hearingloss.org/sites/default/files/docs/pepnet_resources.pdf

Hands & Voices
"Beyond High School"

http://www.handsandvoices.org/articles/education/ed/V13-1_beyondHS.htm

Services for Oral Deaf Students (cochlear implants)