My wife has a Droid 4 phone that recently has begun to chime the same sound it uses for a text message or e-mail alert—only there are no notifications at all. A tiny purple light flashes in the corner at the same time as the notification sound, which happens every ten minutes or so throughout the day. We’ve disabled all notifications that we can find. We deleted the Twitter and email accounts. And yet nothing seems to shut the thing up. Anyone else have this experience?
Probably Yahoo Mail. It’s not a prroblem for me, but others have said they get the purple light even with notification turned off.
I had read that too. But we deleted the e-mail account from the phone, and the problem still persists.
Is there an event setup in the Calendar, possibly with a daily repeating reminder?
There’s someone in the backseat of your car!
EDIT: Poor little phone is trying its damnedest to alert you to the danger your life is in the only way it knows how. 
I was getting a similar alert, persisting despite the fact that I had no new text messages or e-mails. It turned out to be Tapatalk informing me that people were replying to threads I’d replied to on the Straight Dope Message Board!
I’m not even sure what TapTalk is…if it’ something she would have gone out of her way to download, then that’s not it. But if it’s something that’s installed by default…more to the point though, how did you finally figure out what was causing the alert?
I was going to suggest that it was the result of psionic interactions between nearby water spirits and the minions of the cthonic undead, but Tapatalk sounds much more reasonable.
It appears to be a very successful app and it is free.
But, it doesn’t appear to be a preloaded piece of software.
If you don’t have Tapatalk, you might want to download it.
It may, in fact, discourage the water spirits from hijacking your phone to communicate with the underground zombies.
Change the notification for everything you can find to different sounds. If this one then changes, you can narrow down what type of notification it is. If not, well, you didn’t find all the notification settings! You can also look at running services to see if there’s an app worthy of further investigation.
Is there an unread text message? If you read a preview to a text message without opening the app, the message may still technically be unread and the messaging app may be sounding a reminder for missed texts. I haven’t used the stock messaging app, but the one I do use can do that on occasion.
Then it’s desperately trying to get you to change your favorite color.
None of these but she did have an unsent message. I deleted it so now I have to wait and see if the alert goes away
Well, that wasn’t it. Damn this is getting frustrating. I can’t imagine what the purpose is of having a notification sound with no way to figure out what the notification is.
Tapatalk isn’t free.
So you’re sure there are no new notification icons in the notification area? If that’s the case, I’d suspect a widget as the culprit. Widgets might not show up in the notification area since they are already “live” on one of the homepages, and would display their notifications/alerts there. What widgets does she have, and have you checked them all?
If not a widget, I’d reboot the phone, then go to “Menu” “Manage Apps” and check to see what apps are running - your culprit is almost surely going to be one of those. Uninstall whichever ones she doesn’t want/need, and check the others for notifications or settings you can change to turn off alerts/notifications.
Barring any of that, if your wife doesn’t mind starting off with the phone like it was brand-new, she could always do a factory reset.
If you’re interested, you can go to the Play store and download aLogcat, a free app for reading system logs. You could open aLogcat as soon as you get a notification and see if anything looks like it may be the cause, but chances are you won’t recognize it unless you’re familiar with the Android system.
You can email the system log from the app and post it here, but there’s always a slight chance that some apps may leave personal information in the log. I’ve never seen anything confidential in mine, but you can tell the name of some apps that have been used recently and media files. You could open aLogcat, clear the log, wait until there’s a notification, open aLogcat and hit pause so it stops logging, then look through it to make sure there’s no personal info, then post it. You could PM it to me, but there’s no reason to trust me with it.
There’s no guarantee it will show up in the log. I tried a couple notifications and one app logged it and the other didn’t.