I found the solution...
It is probably your docking port needs cleaned.
I carry myiPad in neophrene sleeve an old military canvas medic bag that I use as a messenger bag. The other day I had tossed a pear in the bag in a small plastic sack for my lunch and headed off to the park to enjoy an afternoon of girl watching at the Pathenon area in Nashville (gotta love Vandy and warm days). Anyhow, I had been busy chatting with a few friends who showed up to do some rollerblading and completely forgot about the pear and by the time I got home it had split open from my keys tossed in my bag and had mushed out all over, including through the neoprene and onto my iPad's smart cover.
Now at first I thought no biggie. It didn't damage my iPad and only got the cover damp which I cleaned when I got home and left to dry. But then I noticed my volume would come and go and my volume buttons didn't work anymore. I could not get any external sounds except notification event like incoming email to work at all. Yet when I tried my headphones, they worked le a charm and I could hear everything.
At first I figured it was OS related so I wiped my iPad and restored from iCloud, but after the restore the volume issue persisted. So then I wiped my iPad and started from a clean slate, but the volume issue followed. So now I decided to Google the issue. I read some forum responses and saw others with the same issue so I figured it might be a defect and would have to send it back to Apple for repairs... But darnit I use my iPad daily and can't be apart from my Precioussss.
So I started playing with it, figuring it was going to Apple anyhow, why not try to fix it first. So I examined the rocker arm on the side and it moves freely and doesn't seem to be stuck or anything. Then I checked the settings and function of the lock slide which made no difference. And then I examined the docking port and couldn't see in it well so I put the iPad under my desk light and got out my jeweler glasses I use when cleaning my service pistol... eureka!
Deep in the charging port it looked like it was fouled and had some lint and debris sticking to what looked like some sticky substance... Yep, pear juice.
So I grabbed a micro-circuit chip puller (looks basically like a professional metal dental pick) that I had picked up at my local hardware store (Harbor Freight) for about 2 bucks. I usually use it for cleaning the firing pin area and hard to reach areas of my Sig after range time, and I figured it looked small enough to get down in the docking port. So I used the hook end and carefully removed most of the debris from inside the port and then scraped most of the sticky out. Then I took a synthetic cloth patch from my gun cleaning kit and grabbed a bottle of contact cleaner and got the patch damp (rubbing alcohol should work if you don't have contact cleaner) and I used the pick tool again to push the synthetic patch down into the port and carefully under the plastic contact prong in the port, back and forth to remove the rest of the sticky residue. Finally I took a copper brush (again from my gun cleaning kit... You can buy the brushes separate at Bass Pro, Academy Sports, and sometimes the sporting goods section of Wal-Mart) and used the small single row end of bristles to shine the contacts and knock loose and out anything that might be left (basically use it like a toothbrush and brush the port... And no, a toothbrushes nylon bristles probably aren't stiff enough. Copper brushes work best on contact points).
And after cleaning the docking port... MY SOUND IS BACK AND WORKING PROPERLY! The volume control works again, I have my happy key clicks while typing, the whole nine yards.
So think docking port.
