|
Also known as a sound board or an audio card, a sound card is
an expansion card or integrated circuit that provides a computer
with the ability to produce sound that can be heard by the usercanner
is commonly connected to a computer USB, Firewire, Parallel or SCSI
port.
|
The sound card's four
main functions are: as a synthesizer (generating sounds), as a MIDI
interface, analog-to-digital conversion (used, for example, in recording
sound from a microphone), and digital-to-analog conversion (used,
for example, to reproduce sound for a speaker). The three methods
of sound synthesis are through frequency modulation (FM) technology,
wavetable, and physical modeling
FM synthesis is the least expensive and least effective method.
Sounds are simulated by using algorithms to create sine waves that
are as close to the sound as possible. For example, the sound of
a guitar can be simulated, although the result does not really sound
very much like a guitar. Wavetable uses actual, digitally recorded
sound samples stored on the card for the highest performance. Physical
modeling is a new type of synthesizing, in which sounds are simulated
through a complex programming procedure. Some sound cards can also
have sounds downloaded to them.
Some sound cards have 3-D capabilities enabled by processors on
the card that use mathematical formulas to create greater depth,
complexity, and realism of sound. High quality audio can be produced
through a system that uses the Universal Serial Bus (USB) and does
not require a sound card.
|