The High Definition Multimedia Interface (HDMI) is an internationally standardized connection that allows both audio and video data to be sent over the same wire, simplifying connections and increasing the quality of the video and audio interface. Connecting a television to a laptop with an HDMI cable should allow for the transmission of audio and video over the same wire, but sometimes settings need to be adjusted.
HDMI connections support full high-definition video according to the Advanced Television System Committee (ATSC) standard. Category 1 HDMI cable can transmit 720p or 1080i resolution video, whereas the category 2 (a.k.a. high speed) cable can handle 1080p resolution video and greater. Audio signals are carried over the same cable, allowing for a simple, ubiquitous interface. HDMI cables can handle at least Dolby Digital 5.1 Surround Sound, with revision 1.3 and later supporting Dolby's lossless TrueHD audio quality.
Not all laptops have HDMI connections, so you may need to convert your Digital Video Interface (DVI) connection to HDMI to plug into your HDMI enabled TV. Older TVs may not have the HDMI connection to interface with your newer laptop, so you may need to convert from the HDMI to DVI signal.
Use Separate Audio Cables
If you are using a cable to convert the signal from either your TV or laptop from HDMI to DVI, then the audio portion of the HDMI signal will be lost. In this case, you will need a separate set of audio cables to connect your laptop to your computer. Typically, laptops will use a 3.5 millimeter (1/8th inch) headphone connection and TVs will use an RCA audio input (red and white cables). Get a 3.5 millimeter-to-RCA audio cable to connect your laptop to your TV.
Enable HDMI Audio
If both the laptop and the TV have HDMI connections, then the audio settings in the computer need to be adjusted. Click "Start" then "Control Panel" and "Hardware and Sound." Click "Manage Audio Devices," then click on the HDMI audio device in the list. Click the "Set as Default" button at the bottom of the window then click "OK." Windows will now transmit audio over the HDMI cable.