This thread is a littlebit old but i do this:
install pico2wave via packages.
Create file speech.sh put in this:
#!/bin/bash
say() {
pico2wave --lang=de-DE --wave=/tmp/test.wav "$*"; aplay /tmp/test.wav; rm /tmp/test.wav
}
say $* > /dev/null 2>&1
After this you can do via execute command with a rule like this:
WHEN LVRMoveDetect reports present and $SomeOneAtHome = 0 THEN execute "/home/pi/speech.sh Hallo, Sie haben den Alarm ausgelöst. Polizei ist alamiert."
There are many scenarios that you can do now like a window is open to long. Or put out the weather if change etc etc etc.
Via aplay, you can play also sound files.
Now you have a secure dog wake up all the time and the postman will runaway if you have a big loudspeaker on door.