Hey Everyone, I finally Got it working now!!!!

I did something 'samiux' suggested, which was to install gnome-alsamixer. And checked 'rec' on its interfaces and then tried it out. It worked. Thank you guys for helping out.

Now if someone could explain to me how we could enable the same 'rec' thing without installing gnome-alsamixer? what is this 'rec' check option on gnome-alsamixer's interface corresponds to, on the system?