I would think that if a jw is studying with a minor child under 18, they need the parent's permission. If they have that permission, it is the paren'ts responsibility to a great degree. Educating the parent(s) is the best thing. The WTS has been targetting the deaf and blind for some time, as well as disabled with the promise of eternal good health on a paradise earth. jws target people who are unhappy, disabled, suffering a castrophe in their lives. If non-jws reject them, "oh, they have their paradise on earth already, or think they do."
I saw an elder and his wife target his non-jw cousin who was in a wheelchair, a quadriplegic. After an initial love bombing, people stopped coming up and talking to her (her speech was hard to undersand). When she needed a ride to the meetings when her cousin was on vacation, no one stepped forward, not even the 2 families that had special vans. She was counseled on not coming to enough meetings. Gradually she stopped coming and went back to the church she had been going to whose care and support did not have conditions.
The deaf groups and congregations tend to be made up of hearing individuals "helping" the deaf. I was approached by the president of the non-jw deaf club asking why the sudden interest in the deaf. "A new field" of possible candidates now that less and less hearing are becoming jws. He felt they were preying on these people like too many hearing do. Pretty much like the Spanish-speaking congregations where the children going to school are learning English and forgetting all but the Spanish to talk with family, even a mixture of Spanish and English. Nothing at a theocratic level. Eventually the older children switch to the English or stay because then they don't have to listen because they don't understand it.
I know jws that switched to Spanish-speaking congregations to get away from the image others had of them. These congregations tend to be closer, more family oriented, and welcoming to new people. But...many of these jws do not learn much Spanish and the males do not progress to being MS or elders.
It is good that there is balanced information for the hearing impaired.