I have a Sprint Samsung Galaxy SII that I use on my favorite provider, Ting, and have learned a few things about turning off annoying sounds that are typically not user-adjustable on Sprint phones.
Update: if you do not wish to root your device or want to mute other sounds, check out my guide on muting any sounds with Tasker.
This tutorial was prompted by questions asked on another post, How to Turn of Galaxy S2 Camera Sounds. This adjustment requires that you have a rooted device, but if your device is already rooted it is a very simple fix.
Repeat this process for “Cam_Stop.ogg”, again turning off all of the permissions. Once you have turned off all the permissions the Cam_Start.ogg and Cam_Stop.ogg files should look like this with no read or write permissions: