iOS BUG FIX/REPAIR:
I had the same problem with my iphone 4s. After updating I would get ringtones from my speaker but could not play any music. If I opened the sound recorder I could play sound yet other apps had nothing. I tried cleaning the charging port and headphone jack; however, I knew those were not the problem because I kept my phone very clean. I was certain the glitch was somewhere within the update. After doing much reading about the issue, I noticed many people had luck pluging/unplugging their idevice into a “dock” (which reads/plays audio from the unit). I personally never use my charging port to play audio; I’ve always used the headphone jack. I figured I’d try it anyways. I went to my local car audio store with my iphone and cable and pluged it into a display Kenwood car radio through the USB port. I opened my itunes and played a song. After I heard the music come through the store’s display speakers, I unplugged my phone and hit the itunes “play” button. My sound was restored and my volume buttons once again controlled the volume instead of displaying only the “volume square”. This completely solved the mystery and the problem.
** Note: Prior to going to the store, I did try pluging an unplugging into the standard charger well over 50 times within the two weeks of my sound not working and there was no change **
I’m thinking the people who often use their charging port to connect through data and play audio are the folks who were successful at restoring their idevice’s audio. I also believe many may have misunderstood or misinterpreted their problem as being “hardware related” or “bottom-port” related because it worked for them. There is probably many people who potentially need to clean their bottom port or headphone jack, but this problem is completely different from the iOS update problem. For whatever reason, after updating iOS, some devices may need to see a data/audio device via charging port to rectify the problem of the sound not working.
I hope this helps!!
Mark