Prostate-specific antigen (PSA) is a substance produced by the prostate gland. Elevated PSA levels may indicate prostate cancer, a noncancerous condition such as prostatitis, or an enlarged prostate.
Dolby Digital, formerly known as AC-3, is a digital audio coding technique that reduces the amount of data needed to produce high quality sound. Dolby Digital takes advantage of how the human ear processes sound.
Dolby Pro Logic is a matrixed format. This means that there are two stereo channels (on the VHS tape) and within these two channels exists the data to create a center channel and single rear surround channel (which is split by the receiver to two speakers).owered by the boom in popularity of VHS in the late 1980s, Dolby Pro Logic brought a reasonable, non-discrete surround track to people's living rooms.