It's always happened, but now it's happening more often, as in at least twice every night. I'll be sleeping and then I hear a voice, my dad's or my mum's, calling me. I wake up with a jolt because they always sound mad. I know it's not them because they don't call me in the middle of the night and they leave for work early, so half the times this happens, they're not even home. Does anyone know what this is?