Is it possible to switch between earphones and built-in monitor speakers?

When I plug my earphones into the front panel of my CPU, I get sounds from my earphones. When I unplug it, it goes to the default built-in speakers of the monitor.

Is it possible to set through a software which audio output device it would use? I couldn't find "speakers" being listed in the Playback tab. It only contains one item and it remains like that when I plug-unplug the earphones.

Sound Control Panel

When my earphones are plugged, there is no sound coming out from the monitor speakers. With earphones unplugged, sound comes out from the monitor speakers.

What I want to happen is for both devices to be plugged in and be able to select which device it would use through a software.

Is this possible? I also tried accessing Realtek Audio Manager. Right now, both are plugged (monitor speakers and earphones):

First off... if you examined where your audio header connects to your motherboard, you will most likely find that you don't only have left and right Out, as well as ground connections for each, but that you also have left and right In.

Wait... what?

enter image description here

Image courtesy of Intel (believe it or not).

With some header connectors, there are just two loops (red and white usually, but not always) of wire from the out pin to the return pin.
enter image description here

Image Courtesy of bjorn3d.com However... the whole reason for this out/return setup is simple, and it sounds like your case is making use of it. Better quality cases use headphone jacks that include a physical "switch" within them.
enter image description here Found that image on Tomshardware.it

This is simply a contact that is broken when you insert the 3.5mm plug. When that contact is broken, no return signal is sent to the motherboard, so no audio is sent to the rear speaker port. When the headphone plug is removed from the front jack, the connection is re-established, so the audio signal is sent once again to the return pins, and thus to the rear audio out port.

In newer/better quality motherboards, this can be controlled via software... where if you are using a program that can interact properly with your audio hardware and drivers, you can actually tell the software whether to send audio to the headphones, or the speakers. However, this functionality all depends on having the most up to date drivers, a motherboard that has audio hardware that offers this functionality, and software that offers the ability to send audio to different outputs.

From what you say and show, you are dealing with a hardware function only. You could try to update your drivers, and you can see if you are given "expert" or "advanced" options... enter image description here but it is just as likely (if not more so) that it is just the design of your case front audio header and your specific motherboard that switches your speakers on and off depending on the presence of something plugged in the front.

Thank you everybody. Finally, the answers I've been searching for.

My problem was this: I wanted to be able to switch the audio input between speakers and headphones without unplugging the headphone cable.

This is important for me because my computer is about 5 feet away from where I sit, making me use a audio extension cable. Just removing the headphones from the extension didn't cause the audio to switch so I'd have to get up and reach uncomfortably under a desk every time I wanted to switch audio inputs.

Now I've figured out the solution so that I can switch between speakers or headphones without unplugging the headphones from the hack. I'm using Windows 8.1 BTW.

The first, and really the most important part, was finding the realtek advanced audio options. It's a tiny gear icon along the top of the realtek DH panel. I simply did not see it the first few times I opened this panel searching for a solution.

realtek settings icon

Now, the settings here basically have the solution. Without changing the settings here, both the headphones and the speakers show up as a single audio device. Since they're the same, there's no way to disable one without the other. The "Make front and real output devices playback two different audio streams simultaneously" option is really the golden ticket. Once you click that, you get multiple audio devices what you can enable, disable, or set to default.

realtek options