Answer
The H55H-M's DVI port can output the HDMI (Video + Audio) data by the DVI to HDMI adapter.
Below picture of the DVI to HDMI adapter for reference.
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How to use and setting onboard HDMI audio?
1. Please enter "CMOS Setup Utility/Advanced Chipset Setup" to "Enabled" HDMI Audio function as below picture.
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2. Select "Digital Output Device (HDMI)" of playback device under Windows Control Panel as below picture.
(Please note that below Sound setting under Vista OS for example.)
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