Door Intercom: Door release sound not loud enough for visitor to hear...

THE PROBLEM:
I have a normal apartment (5-wire) intercom system. The system works normally.
We have a lot of visitors and do not need to screen visitors for entry.

I have set up a wireless relay switch so that when the buzzer is pressed by a visitor, the door can be released from anywhere in the apartment by pressing the wireless relay without the need to go to the intercom (down a long corridor).

The only problem is that the door release sound is quite quiet and some visitors are not aware that the door has been released... (Obviously if we use the relay and do not go to the intercom handset, we cannot talk to them to let them know)

THE SOLUTION
I wonder if there is any way we can wire something into the intercom handset in the apartment so that when the door release relay is pressed, a buzz is played over the Visitor's intercom speaker ?

jo murphey said:

We have a lot of visitors and do not need to screen visitors for entry.

Click to expand...

Do the people in the other apartments agree to the main building doors being un-locked by you without the caller being identfied ?

How do you know the caller is coming to see you, it may be a criminal wanting acess to the building.

I would also expect that all of the residents' insurance companies would need to be informed. As you have removed a major security device, on which they calculate claims. You could easily find that an insurance company refuses to pay out a penny.

Two things is the lock dc or ac
Is a failed open or closed ?
If it’s dc failed locked fit a small buzzer across the lock , failed open your going to need a relay
Ac same as above but fit a small bridge rectifier