The flipper above the volume controls whether the phone is on silent or loud. Unfortunately, it may not work right away as when you install the case, if it is not properly lined up, it won't work. Otterbox has created a work around in the you can pull off that flipper and adjust to so that it will work. Just be careful not to do this too many times as it may wear down and cause the flipper to be displaced at a time when you would not want to lose it.