There seems to be some problems with the VOX setup in Vista. Here is a guide to assist those with Vista and VOX seeming to be soft or not working.
Step 1: Go to "START" --> "CONTROL PANEL --> "SPEECH RECOGNITION OPTIONS"

Step 2: Choose "SETUP MICROPHONE"

Step 3: Choose your microphone type

Step 4: Click "NEXT"

Step 5: Position the Microphone and read the "Peter dictates to his....." when the "NEXT" button is available click it.

Step 6: Now click "FINISH"

Step 7: Click "START" --> "CONTROL PANEL" --> "SOUND"

Step 8: Click the "RECORDING" tab then the "PROPERTIES" button

Step 9: Choose the "CUSTOM" tab and make sure the checkbox for "MICROPHONE BOOST" is checked. (this may say "gain control", "Boost" etc)

Step 10: Now click the "LEVELS" tab and move the slider to the right between 80 and 100 setting

Step 11: Start ACES HIGH II and bring up your Clipboard (esc key) choose "OPTIONS" --> "PREFERENCES" --> "VOICE" and move your sliders for the Microphone Volume to the far right

This should allow you to be heard clearly on VOX. I do not like the Channel Beeps so they are disabled for me. This is a matter of preference.
Hope this helps.
TD