the sound of the dripleafs locked in a loop

When I put a redstone block next to the dripleaf to lock it and step on it, the sound plays in a loop until I leave the block.

edit : When you add an observer next to the blocked dreapleaf locked and put some redstone connected to the observer, the more redstone there is, the louder the sound gets.

edit 2: When connecting the redstone to the redstone block the dripleaf sound is played