Its just ambient sounds for atmosphere. There are no other crypts right neaby (usually). Each burial chamber, sunken crypt etc is its own instance placed way up high in the sky well above the branches of Yggdrasil almost directly above the entrance to it in the main world. You can confirm this yourself by using a door in a burial chamber to glitch yourself through a wall. Warning- make sure you have over 100hp when you do this or dont mind dying, because its a loooong way down. I dont know if you can do the same thing in sunken crypts if you find one with an iron gate or not. Speedrunners do have ways to glitch through the walls though, using log benches iirc.