Ok this is weird but honestly the sound of a 심장 beating helps me sleep because it's soo calming. It helps me sleep better and like when hear someone's 심장 beating it makes me feel all weak and just sleepy but in a 안전한, 안전 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 심장 is gonna pop out of their chest 또는 something cuz it's at a steady beat. And it's 음악 to my ears.