Just shout “ding dong” as loud as possible
We have to emphasize this from the start: if we saw this in person, we’d be laughing so hard. We had a good chuckle about it even before we read it for the first time. We enjoy most that the sign does not urge visitors to strike loudly or anything similar.
No, it won’t. Just say, “ding dong,” and it will act like an actual doorbell. Imagine walking down the street while hearing various people shouting, “ding dong.” That would be an intriguing occurrence for sure.