Why can i only hear out the right side of my headset

Why can i only hear out the right side of my headset?

Well i noticed this when i was attempting to talk to someone over skype but i could barely hear them considering only one side of my headset works... Can anyone please tell me how to fix this problem, if there is even "fixing" it, also it's not just skype i tried listening to some music... Dat' failed xD , so yeah, please tell me a way or if it's possible to fix this :D thanks for any answer