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