In Netflix’s “Hush,” a deaf novelist, Maddie (Kate Siegel), has to compensate for her deficiency. She has a deafening fire alarm that can alert her to danger because it causes vibrations. She constantly has to keep an eye on her phone because the ringtones we’re so accustomed to are no help to her. The only things she can hear are the voices in her mind, all of them taking the guise of her mother’s.