built in speakers

I have the 360 Elite, a computer, and a monitor with 1x hdmi, 1x vga, and 1x dvi inputs (Acer gn246hl). There are no built-in speakers. How can I get audio from the xbox? I would like to use my headset (Creative SoundBlaster Tactic 3D Sigma), but I will take any option at this point. The...