PC Hardware in a Nutshell, 3rd Edition

PC Audio Types

Sound cards support two categories of audio, which are detailed in the following sections:

Waveform audio

Waveform audio files, also called simply sound files, store actual audio data. When you record waveform audio, the sound card encodes the analog audio data in digital format and stores it as a file. When you play waveform audio, the sound card reads the digital audio data contained in the file and converts it to analog audio, which is then reproduced on speakers or headphones. Waveform audio files can store any type of audio, including speech, singing, instrumental music, and sound effects. The playback quality of waveform audio depends primarily on how much detail was captured in the original recording and how much of that data, if any, was lost when compressing the data before storing it on disk. Uncompressed waveform audio files (such as .WAV files) are large, requiring as much as 10 MB per minute of audio stored. Compressed audio files may be 1/20 that size or smaller, although high compression generally results in lower sound quality.

MIDI audio

Rather than storing actual audio data, Musical Instrument Digital Interface (MIDI) files store instructions that a sound card can use to create audio on the fly. MIDI audio files store only instrumental music and sound effects, not speech or singing. Originally used almost solely by professional musicians, MIDI is now commonly used by games and other applications for background music and sound effects, so MIDI ...