Sound Driver

[shivanandb]

I have installed Ubuntu 14.04. Recently i pluged my ear phone to my system after that i am not able to hear the sound through my speakers. I checked the sound settings there i saw the output as headphones. How do i change or add speaker driver into this. I have windows 8 also, faced the same the same problem, but there i made the speakers as default outpu and i got the sound back to the speakers.

Can anybody please help me in this regard. I even reinstalled Ubuntu, but still facing the same issue.
/home/shiva/Pictures/Screenshot from 2014-05-03 12:25:03.png