Speech Synthesis after a window has loaded

Hi

When a window fully renders on screen and everything displays i want Speech synthesis to kick in.

SpeechSynthesizer synthesizer = new SpeechSynthesizer();
synthesizer.Speak("Welcome to the Projects Database");

What event do i use on the window to trigger it? 

Loaded doesn't seem to do it. It runs the voice just before it displays the screen.

Any ideas?

Regards

Conor