PC sound glossary. (Compute's Getting Started with PC Sound) (Glossary)
by David English

analog. An audio signal whose fluctuating voltage pattern reflects the structure of the original sound. See also digital.

CD-DA. Short for Compact Disc-Digital Audio. Also known as Red Book audio. The CD-quality audio that comes directly from a conventional audio CD or CD-ROM.

digital. An audio signal that has been converted into numbers that no logner directly reflect the structure of the original sound. See also analog.

Hz. Short for Hertz. A unit used to measure the frequency of a vibrating object, such as a violin string or the cone in a speaker. Also known as cycles per second. The human ear can hear from approximately 20 Hz to 20 kHz (20 to 20,000 Hz).

MIDI. Short for Musical Instrument Digital Interface. Pronounced "middy." A digital communications protocol that allows electronic musical instruments and computers to communicate with each other. Because MIDI sends performance information (such as note on, note off, pitch change, and volume), rather than actual musical sounds, it's a highly efficient way to store and transmit musical data.

MIDI interface. A serial hardware device that allows a computer to send and receive MIDI data.

MPC. Short for Multimedia PC. Any computer, upgrade product, or software title that conforms to the standards set by the Multimedia PC Marketing Council.

multimedia. The combination of graphics, sound, animation, and video in a single software program. Sometimes only two or three of these elements are needed in order for a program to be called a multimedia program. Can also describe any PC, upgrade product, or software title that conforms to the MPC standard.

sound board. Also known as a sound card. An expansion board you place inside a PC that improves the quality of the PC's sound output. A program must support the sound board before it can benefit from the board's improved sound quality.

synthesizer. An electronic musical instrument that can generate simple or complex sounds. Most synthesizers include a MIDI interface and a keyboard, though synthesizers without a built-in keyboard (called sound modules or expanders) are becoming increasingly more common.

waveform audio. A technique for recreating voice and sound effects using digital audio samples. Under Windows, waveform audio generally is stored with the WAV filename extension.