GM My 89 Y.o.'s Helper For My Mother Is From

GM My 89 y.o.'s helper for my mother is from Haiti. Her younger sister of 8 began hearing voices in her teenage years. I know that schitzophrenia can happen in your teenage years....however, her none of her siblings have it. Could this be an inner ear problem since our helper told us she swam a lot and loved to be in the water? Could in inner ear prob. cause you to hear voices?