You can silence or adjust the volume of camera sounds.

Muting Sounds

Display the menu.
Press the n button.

Choose [Mute].

Move the zoom lever to choose the 3 tab.
Press the op buttons to choose [Mute],
then press the qr buttons to choose [On].
Press the n button to restore the
normal screen.
Changing the Sound Settings
You can also mute camera sounds by holding down the p button and
turning on the power.
If you mute camera sounds, the sound will also be muted when playing
back movies (p.31). If you press the o button while playing back a
movie, the sound will play back, and you can adjust the volume with the
op buttons.