I tried searching but I'm not sure what it's called, I'm sorry. The switch above the volume buttons on my 4S stopped working today. I switched the sound off going into work as I do every day but the sound still worked. I switched it on and off a few times thinking it didn't "settle" right, even turned the phone on and off to see if it was a software bug. Still makes sound. Turned the volume as low as it goes and stuffed it in my purse. Any thoughts? Don't know if there might be a trick to this or if perhaps Apple will just replace the phone like they tend to do for hardware issues.