Ok I have the SONY HANDYCAM that has 80gb of storage: here's the steps,,,
1. press MENU
2. at the bottom left of the screen press SHOW OTHERS
3. use the scroll arrow on the left side of the screen and scroll down to the wrench looking tool (it's all the way at the bottom)- Press it
4. select SOUND/DISP SET
5. Press BEEP
6. Select OFF
That should do it- if you have any other questions about this- let me know!