A Soundless World a World War 2 book

Annie is a German during World War 2 yet Annie is still taken to concentration camps because she's deaf. The unusual thing about Annie's deafness is that she can read lips and talk. This is only possible for her because she had caused her deafness only a year before the war so she already knew how to speak and could tell what people were saying if she had known the words before her fatal accident. While in concentration camp Annie meets a boy who has no deficiency but was brought to the camp only because he had fought to protect his, also deaf, younger sister. Will these two grow to be friends or even more? Will they survive the camp? Will Annie ever hear again?