My double email notifications have gotten so annoying that I had to turn off the audible alert.
This has been going on since I bought my iPad in Feb and just started on my iPhone after restoring it as new.
I've reported it on the Apple site after each update.
This has been a known issue before back during iOS 5.
I still can't believe I wasn't addressed with iOS 6 or iOS 6.0.1
Have a great weekend.
For double txt tones, have you gone into Settings -> Notifications -> Messages and checked the "Repeat Alert" setting. The default is to repeat it once so that you hear it twice.
This was already suggested (first reply, actually). However, that's not the issue they are talking about. The issue in question is the tone going off twice rapidly, with the sound of the second alert often overlapping the first. If your phone is jailbroken and you have IntelliscreenX and Xmessages installed, this often can cause this issue. I've tweeted and emailed Intelliborn multiple times asking them when a fix will be available and never received any response from them (pretty poor customer service).
This problem was solved on my iphone 5 by going to
imessage - turn imessage off
then go back and turn it on
go to send and receive and make sure only one phone number is checked
that fixed it for me