Dolby has specifically developed three types of “virtual” surround processing for computers, computer games, and video games. In “virtual” implementations, “phantom” speakers are created, as processing provides perceived sound sources in addition to the actual speaker complement. Virtual Dolby Digital is a computer format implementation of Dolby Digital. For this method, first a Dolby Digital decoder decodes the digital bit stream and 5.1 channel signals are produced. Then, a “phantom” channel is created providing a perceived center channel where none exists, and the two surround channels are processed through an additional DSP circuit and changed to “virtual” surrounds. All channels of information are provided through only two speakers. This system works best for a single listener who is centered between the left and right speakers. In the Virtual Dolby Digital implementation, some computers will decode the digital bit stream via a Dolby Digital decoder with the ability to “downmix” the 5.1 channels into a Dolby Surround encoded stereo signal. These two channels will then go through a two-channel sound card and be processed through an outboard or inboard Dolby Surround Pro Logic decoder to provide four channels of sound — Left, Center, Right and Surround. The center channel can be switched to “phantom” mode if desired, but four speakers are needed for the left and right front and the two surround speakers at the sides or rear of the listening position.