Nikon D3300 - Manual (Page 90)

70 More on Photography
Choose this mode to keep camera noise to a minimum. A beep
does not sound when the camera focuses.
1
Press the I (E/#) button.
2
Select J (Quiet shutter
release).
Highlight
J (Quiet shutter
release) and press J.
3
Press the shutter-release button all
the way down.
Press the shutter-release button all
the way down to shoot.
Quiet Shutter Release
I (E/#) button