In one scene you can clearly see a clear hearing aid in Anna's ear. As there is no mention of hearing loss in the movie, I assume the hearing aid is real and necessary for the actress. I noticed in her bio that she knows American sign language. Anyone know anything about this?
shareThe white noise generator?
shareThe thing that goes in her ear is necessary for the memory-fishing/re-visiting thing that John is doing with her. I'm not clear on the specifics of what it does, but he mentions it early on, when they re-visit Anna's first memory sequence.
Taissa Farmiga does know ASL, and apparently took it for four years throughout her time in school. To my personal knowledge, she is not hard-of-hearing. The earpiece is simply a prop used in the context of the scene, and it is explained as such.