Hi,
Please get an ENT exam done to rule out hearing problems. It will also help us to know if this thing has started recently. F it is a recent occurrence there is a possibility that the child is under some kind of stress or anxiety. I would suggest you to try and talk to her about it.
Well, first off, she should have her ears examined by an ENT ear-nose-throat doc. It's very likely she has a hearing problem. She may not be hearing certain frequencies, so she needs a bona fide hearing test done, where they put headphones on her and she listens to a range of ringing sounds.
The other possibility I am not sure of, because apparently this just started and was not a feature in her childhood, but autism or one of its milder forms, they all have different names, could be what's going on. See, one theory of autism is, it comes from sensory overload. Everything around them kind of echoes on top of each other because their information processing center is deficient for some reason. So, the child withdraws within theirselves and focuses on "array" type things, like reflective objects, repetitive movements, where the broken flow doesn't matter and in fact is comforting.
So, go to the ENT doc and also have a hearing test done first. She may just need a hearing aide or therapy in how to cope with frequency hearing loss. If she's okay, then you can go to a psychiatrist or specialist who does nothing but treat autistic disorders, and have him decide which one she has and how to go about training her to focus, even tho the world is swirling around her.
They recently had a young lady on "America's Next Top Model" who had a form of autism, and she made it to the final five, lovely person, kind of quiet, and she had learned over the years how to concentrate well enough to enjoy an exceptional young adult's life.