Ok this is weird but honestly the sound of a herz beating helps me sleep because it's soo calming. It helps me sleep better and like when hear someone's herz beating it makes me feel all weak and just sleepy but in a safe, sicher feeling way. Like im secured forever in their arms. So yea heartbeats help me sleep :) I like to lay on a man's chest and just hear the beating in my ear and I fall asleep and it's like their herz is gonna pop out of their chest oder something cuz it's at a steady beat. And it's Musik to my ears.