Is there a way to disable the beep on Shut Down?

[Charlie Brune]

Whenever I select the "Shut Down" menu option to turn my laptop off, my 
laptop emits a loud beep.

Is there a way to keep the beep from happening?  It's pretty loud and 
tends to wake up anyone near me who's sleeping.

I've already gone to the "Sound Preferences" screen and de-selected the 
"Play Alerts and Sound Effects" option.  That doesn't stop this beep.

Thanks,
Charlie
St. Louis, MO.