No idea, the door bell itself does go ding dong or at least the last one I installed did that's the 12V model, within a second or so the smart devices its assigned to are all calling in and waiting to be accepted.
So not sure its a big issue, unless your in without a smart device with the door bell assigned to it. so you may not hear the external ding dong.
I let you know if I ever find a solution to the 12V door bell chime, not found a made to measure solution as yet.