She's new in town, fresh off the train, and so very, very ready to get away from people. A quick stop inside the train station to sit and listen gives her a detailed map of the surrounding area - everything within a few miles - and lets her pick out a few potential hiding places. It's a simple use of her power, listening to all the tiny little sounds and letting them tell her what's going on around her, where things are, where she is.
She picks a spot - a disused bit of a storm sewer, bone dry according to the acoustics - and starts making her way there, effortlessly finding a route that lets her avoid being seen or heard. It's pretty far from the train station, and she munches on a granola bar as she goes; she's got a few days of food in her pack, enough to last until she's worked out which stores are safe for dumpster diving. For now, she's not going to worry about it; she just wants to get herself hidden away so she can finally relax.
Getting into the sewer is easy; there's a padlock, but her superpowered hearing makes it trivial to pick. Then it's just a matter of following the map to get where she's going... until suddenly, with a flash of light, it isn't.
She can't hear.
She can hear. She can hear everything. Ever since she got her power, sounds she wasn't paying attention to would... slide back. Tuck away. Politely wait their turn. Vision was still a cacophony, sometimes, smell and taste and touch still threatened pain and overwhelm even on the best of days, but sound, sound had been her friend, only to betray her. She hears everything, everything in her new, tiny, unaugmented range, whether she wants to or not.
She doesn't know where she is. She doesn't know what happened. She's barely aware of her body - she's fallen over, it takes her a few moments to put together. There are people, she can hear them. Whatever happened, she's found, she's found, they're going to send her back...
She curls up into a tight ball, operating solely on instinct, and screams and screams and screams.