Audio cards are known as a computer expansion card which are plugged in to record and play back sound. They act as an input port for sound source like micro phone and output ports like speakers and amplifiers used in various music composition, presentation, education and entertainment. The most commonly found in the market are 2 port USB sound card,PCI sound card ,creative sound blaster sound card, Pinnacle video transfer,techcom sound card 4 and 6 chnannels,creative X-Fi surround soundcard, creative PCI express sound blaster X-Fi titanium sound card and many more at variable prices.