Dolby are renowned for their surround sound audio codec technology. One of their most recent creations is TrueHD. As the name would suggest, it refers to high definition surround sound.

When consumers think of high definition, they usually assume it to be a screen display technology. For a television to be classed as HD, it is required to have 720 or more vertical resolution lines.

So, when it comes to high definition sound, was are it's properties? Dolby refer to the facets of their high definition surround sound as the following,

• 100% loss less audio
• 7.1 channels (seven speakers and a subwoofer)

Dolby TrueHD is seen as an upgrade of AC-3 Dolby Digital. While TrueHD support 7.1 channels, Dolby Digital was designed for 5.1 channels.

Dolby Digital was a standard sound codec for DVD discs. Whereas TrueHD has been designed for Bluray discs. Therefore, to take advantage of TrueHD, you'll need a cinema system which supports Bluray, TrueHD, and of course a bluray disc which features TrueHD.