Sound can be an important part to any computer system. Some multimedia applications make great use of sound, but a sound card is needed to take advantage of them. Not only can you play music through the computer, but even if you know nothing about music, you can compose music. A computer is a good way to convert text and graphics into digital data. Music can also be digitized, and then it can be rearranged, edited, and other improvements.

Sound Cards

There are some very inexpensive sound cards on the market today. But to receive the best performance you have to spend a little bit more money. Sound cards should be able to record narration, sound, or music and store it as a *.WAV file. You should also be able to change the sample rate and be able to record in both mono and stereo. Also, a good sound card should have MIDI (musical insrtument digital interface). MIDI allows users to connect certain devices, such as piano keyboards, synthesizers, or sound modules, to the computer itself. MIDI is allowed because of FM synthesis. FM synthesis, either software or hardware, allows MIDI to recreate up to 128 MIDI voices and 46 instruments.

Some of the better sound card are made by:

Creative Labs, Ess, Yamaha, Ensoniq, and Diamond Multimedia. (Links to drivers can be are available at the end of this page).

Sound, Microphones, and Speakers

Sound is created when an object vibrates and makes sound waves. If a microphone is placed by sound, it can transform it into electrical impulses. The basic microphone has a diaphram that vibrates as a response to pressure from sound waves. The diaphram is conected to a coil of wire that move in and out of a magnetic field. Movement of this coil causes various amounts of analog voltage to be produced. This voltage is then recorded as a series of impulses, and when amplified can be reproduced on a speaker.

A speaker is quite similar to a microphone in structure. The speaker has a coil of wire that is attached to a speaker cone. The coil of wire is also surrounded by a strong permanent magnet. Moving the coil by the magnet creates a voltage, thus producing a magnetic field. As positive and negative pulses are passed through the coil of wire, it alternately attracts the coil into the magnet and forces the speaker cone outward, thus producing sound.