What's new in PC sound. (personal computer audio technologies introduced at 1993 COMDEX in Atlanta, Georgia) (Column)
by David English
COMDEX is never dull. It allows companies to trot out their latest hardware and software for the rest of the industry to see. This year's Atlanta COMDEX showcased two impressive PC-based audio technologies.
The first involves a new chip from Yamaha. If you have a sound card in your PC, it most likely has a Yamaha OPL2 or OPL3 chip. It's the chip that gives you Ad Lib compatibility and allows you to add music and sound effects to your PC games. These chips are actually simple synthesizers that can simulate (with varying accuracy) musical instruments and electronic sound effects.
Most sound cards also have chips that let the card play back recorded sounds. These chips let you hear narration and real-sounding music and give you what most people refer to as Sound Blaster compatibility. This kind of sound is very realistic because the actual recorded sounds are stored on your disk or CD-ROM. On the downside, they take up huge amounts of disk space--as much as 10MB a minute when recorded at CD-audio quality.
A third kind of PC-based audio is called MIDI (Musical Instrument Digital Interface). MIDI is an electronic communications standard popularized by the synthesizer companies. An extension of the standard, called General MIDI, has become so popular on the PC that some sound cards now have General MIDI built in or offer it as an add-on. Most General MIDI systems use a wave-table technology where the sound of an instrument (such as an organ or trumpet) is stored in a ROM chip. The musical instruments sound very realistic because the actual patterns of the sound are used to re-create the sound. And because MIDI files basically store only note-on, note-off, pitch-change, and instrument-change information, General MIDI is extremely efficient--often 1/100 the size of a WAV-based audio recording.
Soon, every sound card, even the inexpensive ones, will be able to include General MIDI. At COMDEX, Yamaha announced its new OPL4 chip, which is essentially an OPL3 chip with a built-in 2MB General MIDI ROM chip. An optional chip, the YSS225 Effect Processor, will let you add high-quality sound effects, such as echo, reverberation, flange, distortion, panning, and surround.
Why should you be interested in adding General MIDI to your sound card? If you play games, you'll hear dramatically better music (check out The 7th Guest and X-Wing, and you'll wonder where they're hiding the orchestra). If you're into music, you'll have the guts of a high-quality synthesizer on your sound card. Add an inexpensive MIDI keyboard, and you'll have a music workstation. And check out Musitek's new program, called MIDISCAN for Windows. Scan your sheet music with a hand-held or flatbed scanner, and MIDISCAN will convert it to a standard MIDI file that you can play on your General MIDI sound card.
The other interesting development in audio technology at COMDEX was the growing number of sound cards that feature a DSP (Digital Signal Processor). A DSP is a separate processor that can run specialized programs independently of your computer's main processor. Creative Labs announced that it will support the three-dimensional QSound technology with the Sound Blaster 16 ASP's built-in DSP processor.
Centigram showed its TruVoice text-to-speech software that converts spoken English or Spanish into natural-sounding computer speech. Dragon Systems demonstrated DragonDictate, its advanced voice recognition system, which has a 30,000-word active vocabulary. Both programs will be available for sound boards that use Analog Devices DSP chip.
SierraSemiconductor also announced QSound and voice recognition for its DSP chip. Interplay will be shipping a special voice recognition version of STAR TREK: 25th Anniversary with many of the sound cards that use Sierra's DSP (also known as the Aria chip set).
As you can see, sound cards aren't just for game music anymore. We're about to see a revolution in the PC's ability to work with sound.
New Multimedia Section
Starting with our November issue, COMPUTE will have a monthly eight-page Multimedia PC section, and that's in addition to our usual multimedia reviews. Each issue will include this column (renamed "Fast Forward"), a four-page multimedia feature (with special emphasis on how-to and product-round-up articles), a one-page multimedia product spotlight, and two pages of the latest multimedia products.