I know white cats are more likely to be born deaf, but any cat could have hearing problems. Definitely have your vet look at her. At my old job, we had a deaf cat that lived in the offices (actually, she ruled the roost) and she was just fine. She would even look at you if you said her name. My boss said the vet explained it to him like this. Since cat's whiskers are so sensitive to air currents, if they don't have their hearing to rely on, the whiskers become even more sensitive and start reacting to vibrations, such as voices. She learned what her name felt like. It makes sense. When humans lose a sense, the rest compensate so I guess it could happen to cats too. But, get her checked just to make sure.