Sound Cards are Parallel Port cards, however, some motherboards come with onboard audio. A Sound Card is needed for all sounds other than those produced by the motherboard itself. (the motherboard beeps are used only when the computer has a hardware configuration problem.)

       Dolby Digital 5.1 is the lowest sound quality a computer should have. This can be achieved by purchasing a Creative Labs Sound Blaster LIVE! card. Some motherboards like the MSI KT400 Platinum board come with Onboard Dolby Digital 5.1 surround sound, which is cheap (cause you don't have to buy a sound card AND it frees up a PCI slot for something else)

Creative Labs Audigy Platinum eX