“Zakariyya turned up his hearing aid and leaned close to Christoph and his paper. ” pg.264
Zakariyya seems to turn his hearing aid on and off depending on wether he wants to listen or not. Earlier, when Skloot first met Zakariyya, he had turned it off to avoid listening to the children and now he had turned it off to shut off all the noises from the lab. It is extremely interesting to think about this control over reality that he has, like he can sometimes manipulate it to make it more favorable, to only include what he wants in his life, something that is surely necessary after having lived that kind of life that he had.
The Lacks children didn’t even know that they were deaf until they were nearly adults, they were kept in the dark without even knowing that they couldn’t hear. This is kind of like their situation with their mom, they spent half their lives in the dark.