Olympus Camedia C-740 Ultra Zoom Reference Manual page 146

You can turn off the beep sound used for button operations or warnings
I
1
Mode dial
In the top menu, select MODE
MENU --) SETUP --) =))) --) OFF, and
press @.
_- '"How to use the menus" (P33)
• Press 0 again to exit the menu.
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14s !