I know this might be a stupid 質問 but I can't never figure it out, why don't ヴァンパイア have ハート, 心 beats? Like I know their hearts beat but like how come あなた can't hear it?

Depends on what lore あなた follow. If you're going with the 'all ヴァンパイア do not have heartbeats' it's proooobably because they're dead.
However, if あなた ask me, they just have exceptionally strong hearts, so they don't have to beat fast または hard to ポンプ the blood around the body. (Sorry, I'm a bit of a science nut, I like to make things sound possible. ヴァンパイア included.)

Well, one obvious reason is that they're dead.

i have my own theory, i think its cuz they have a heartbeat but its just quiet because it doesn't need to work as much to keep them alive. also maybe only other ヴァンパイア can hear it and just not human?, i don't know but i'd just go with what あなた wanna believe in. i mean with all the vampire stuff everyone pretty much has their own version

because they are nondeath

Actually, their hearts do not beat. ヴァンパイア are dead. They are a spirit in a dead body, which is why they sometimes are called "damned". Since they are dead, their ハート, 心 does not beat and the blood they drink is the only thing that can provide them the energy they need.

Don't worry, this isn't a stupid 質問 ;)! I had a whole philosophy class on ヴァンパイア last semester, it was awesome ;) and it helped me now so much about vampires!

あなた talk like あなた met a vampire または something. It all depends on whose vampire あなた are talking about, if they are the version that aren't dead then their ハート, 心 beats, if they are the version that are dead, then their hearts must likely don't beat. One funny 質問 though, what do あなた mean hear it, who's hearing it, so far as i know a human can't even hear another human's heartbeat unless with a stethoscope, または maybe leaning in close