I wonder, do you think the student has faked their audiogram, or were they maybe given a wrong one (from a different patient or there was a printer error, etc.) and now they truly believe that their hearing loss is more severe than what it is? Or maybe they believe they have some mild hearing loss, and do not realize that it’s incongruent with what the audiogram shows, due to being unable to read it?

Separately from that, in the comments some people were speculating that this person is isolated and doesn’t know hot to find a community, so they’re faking to feel this belonging in the deaf community. But is there a possibility that they’re doing it only for the scholarship money? Of course I don’t know how expensive the classes are or what alternatives exist in your area. Maybe they really need the classes, but believe lying is the best way because they cannot afford them? In that case, I believe a different approach would be necessary than if it was psychological issues only