I have a client that wants to trigger a doorbell or similar when someone is at the gate. The damn housekeeper misses the Amazon, UPS or whoever and the homeowner doesn't get her crap. She says, "that this system is useless, I don't get my packages". The damn phone rings a double ring tone!! The housekeeper probably has earbuds in, talking to someone!!
Either way, I need to figure out a way to "make some noise" when the Doorking button is pressed. I have a fair amount of telephone jacks around the house I can repurpose for an actual doorbell, etc.
I'm posting this before I look at Viking Electronics. I know they have a lot of telephone triggering devices, etc. But figured I'd throw it out their and see if anyone has done something similar.

What do you want? What's your golden solution?
Do you want deaf people's flasher or lamp blinking?
Do you want sirens?

What control system do you have?

To trigger some type of ringers, doorbells. Blinking lights would probably be a bonus!!
Don't need sirens.
Total Control (early CCGEn stuff) only in the Media Room. BUT now that you ask I have a Russound house music system. It's a MCA-C5. I just looked and it has a paging input. Maybe that could be used with some other devices.

I only looked at it briefly at the manual, but it looks like there are relays that can be used to trigger anything you want. This is what Mario was referring to, except I don't see that a control system needs to be used. Put some kind of bothersome noisemaker under control of one of the relays.

Is it that simple?

Have doorbell trigger control system that starts megadeath at 90% volume on all zones.

Ernie, you're right in that control system is not necessarily a deal breaker.
Control system could make multiple things a breeze to trigger.
Lights, Tv's, D/A, buzzers, SMS, picture or video on touchscreens, timers, schedules, flags/variables (annoying sounds when owners are away), and on, and on.