Pentax Optio M20 Operating Manual page 152

7
Use the four-way controller (23) to select [1], [2], [3] or
[Off] and press 4 button.
The selected sound type is saved.
8
Set [Shutter Sound], [Operation Sound] and [Self-timer
Sound] in the same way as in Steps 5 to 7.
Select [On] or [Off] for the self-timer sound.
9
Press the 3 button.
The screen returns to the [B Setting] menu with the changed setting.
8
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