What may not come to mind at first is that you can also record WAV files with 1AVCenter and therefore you can join both features.

So, to apply your own alert message you need to first 'record the audio message in WAV format'.

Then you need to switch to the 'Surveillance Monitor WebCam' profile using the 'Profile Selector', or the 'Profile Toolbar', or the 'Profile Menu' 'Switch To' option.

Then, on the 'Surveillance Monitor Tasks' dialog check the 'Play sound' checkbox, click 'Browse...', and select the WAV file you have recorded earlier.

After surveillance monitoring the WAV file you've recorded will be played every time activity is detected.