How to get sound with VC 500 device with a Sony Handycam Hi8?

I have a Handycam Hi8 video camcorder. I recently bought a Diamond One Touch VC500 device to transfer my videos to my computer. I have windows vista 32 bit computer. I have the s video cable and the av video out for the camcorder. I can see the video but no sound is being transferred to the computer. The volume is up.