[Al Skierkiewicz]

Ryan,
Audio alerts can take many different forms. If you are trying to get someone's attention, a Sonalert or Piezo electric transducer works very well. These devices work best at their resonant frequency but can reproduce a range of frequencies in the mid band of human hearing. They are easy to interface and are pretty cheap. I have a used a few from Radio Shack like the ones here...http://www.radioshack.com/family/ind...032058.2032230