(such as Dolby Digital or DTS), providing a high-quality approximation of TrueHD audio over a legacy TOSLINK cable for those that do not have HDMI. The Phantom of the Opera , released April 18 , 2006 on HD DVD , was the first movie to offer a TrueHD soundtrack. http://en.wikipedia.org/wiki/Dolby_TrueHD Posted by Marilyn at 8:10