Resolved System Sounds Not Working (Huge Issue)

[Dj64Mk7]

On my iPhone 4s that is running iOS 7.1.2, I am running into a super-problematic issue: the system sounds (ringtones, text tones, lock/keyboard, etc.) aren't working. Even with the ringer at 100%, and not on silent, none of these sounds are working. This is an extremely big issue for me.

Strangely, the vibrations still work, and alarms go off without a hitch.

EDIT: When headphones are plugged in, the sounds will go through the headphones with no problems whatsoever.

Can anyone help me with this serious issue?

 

[Crazy Badger]

Did you fix this? Think my girlfriends 4S is doing this, although not sure if it's related to 7.1.2 or was happening before.

 

[jr866gooner]

My ip4 did this and I was missing calls etc. think it was the port that played up then the phone thought it was docked when it wasn't.