Missing HDMI Audio Playback?

I have my tv and monitor connected with hdmi cables, both showing video, but my playback devices in sound management only shows one playback device that works. I want to switch audio playback between monitor and tv, but they share the same playback device. I noticed when I plug them in separate from each other that they use the same audio playback, "Digital Audio (HDMI)". So how can I get the sound to switch between tv and monitor?

Tried...
Testing default playback on all shown devices (only "Digital Audio (HDMI)" played sound and only on tv or monitor)
Displaying disabled/disconnected devices(no new devices are shown)
Installing/Reinstalling video and sound card multiple times (this would change the name for hdmi audio device to "ATI DP Audio Output" or "AMD Digital Audio" or "Digital Audio (HDMI), despite installing the same driver)

When I watched videos of people fixing sound issues I noticed their audio playback devices were named after the monitor, but for some reason mine isn't and it even shares the same audio playback name for both tv/monitor.

Windows 7 64bit
Video Card: Dual Radeon 5900s
Sound Card: AMD

Can you post a picture of the Sound Panel Playback section and of the Device Manager, Sound section.

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Normally, both are listed in the Sound Panel playback section, If an HDMI cable is plugged in it automatically sets the HDMI as the default audio playback device. If the HDMI cable is disconnected from the PC it will switch back to "Speakers" (the PC sound card). You should also be able to manually set the Speakers as the playback device with HDMI connected.

OK, sorry I missed that.

I see "Display Port", which I assume is your PC Monitor. I don't see an output for HDMI audio (other than SB Xfi which is not the HDMI audio).

Two things I see, (1) Disable the on-board audio in the BIOS when using a separate sound card (the SoundBlaster Xfi) to avoid any conflict. (2) I only see "High Definition Audio Device" for the Display port which suggests the correct driver is not installed for the Display Port and maybe HDMI audio. The "High Definition Audio Device" is only the generic, basic function, Windows installed driver. The correct driver for your CPU video or video card is needed (e.g. if you have an Intel CPU with the built in Video, you need the correct Intel CPU Video/HDMI Audio Driver.

Here is my Device Manager/Sound section. Both my Video Card audio (AMD) and my Intel CPU (i7 3770) Intel Display Audio are listed (and my Realtek).

Edit: I did what you asked, but there still isn't a way to switch audio between my two screens. I am using duplicated screens by the way. When I disconnect the screen with audio the playback device says not plugged in and no other devices will give sound until I restart my computer then my screen will have sound.

Exactly how are you connecting both HDMI screens?

My AMD HDMI shows more than one HDMI output. Your screenshot only shows one. That may be the reason/problem(?)

Here is a screenshot of mine. I have an AMD Radeon 7770 Video Card.

Yes thats exactly my problem. Why is one missing? I have them both plugged in and both show video and are selectable in catalyst control center but only one sound playback device is shown. Also catalyst control center says both screens have no sound, despite the sound working on both of them when plugged in individually and on one of them when both plugged in.

Edit: I updated ccc and now it doesn't even have a audio option.

Uninstall the AMD Video in the Device Manager, Including the Driver. Restart the PC and Windows will install a generic video driver. Then reinstall the AMD driver and see if that helps.

PC spec's, including Video card would help. Please fill in the "My System Spec's". Helps us to try and help you.