Although sound features in computers have become commonplace, the demand for sophisticated uses for sound hardware have grown and demanded more and more powerful hardware. If your idea of a perfect multimedia PC includes any of the following, the plain-vanilla multimedia hardware found in many of today's PCs won't be sufficient:

• Realistic 3D and 360° sound for games

• Theater-quality audio for DVD movies

• Voice dictation and voice command

• Creating and recording MIDI, MP3, CD-Audio, and WAV audio files

Gaming

Thanks to the widespread availability of audio adapters, game playing has taken on a new dimension. Support for 3D and surround digitized sound and realistic MIDI music in current games has added a level of realism that would otherwise be impossible even with today's sophisticated graphics hardware.

Mere stereo playback isn't good enough for hardcore gamers who want to be able to hear monsters behind them or feel the impact of a car crash. These users should choose sound cards with support for four or more speakers and some form of directional sound, such as the Creative Labs EAX technology used in Sound Blaster Live! and the Audigy/Audigy 2 series or Sensaura 3D Positional Audio (3DPA) used by ESS, VideoLogic, Cirrus Crystal Logic, Analog Devices, C-Media, and NVIDIA.

Many sound cards feature support for these standards, either through direct hardware support or through software emulation and conversion. As with 3D video cards, most cards today merely need to work with the 3D audio APIs included in the current revision of Microsoft's DirectX technology.

Any audio adapter built in the last few years will still work with today's games, thanks in large part to the Hardware Emulation Layer (HEL) built into DirectX. HEL emulates the features of newer hardware, such as 3D sound, on older hardware. However, as you can imagine, the task of emulating advanced performance on older hardware can slow down gameplay and doesn't produce sounds as realistic as those available with today's best audio adapters.

Sound Card Minimums for Gameplay

The replacement of the old ISA Sound Blaster Pro standard by PCI sound card standards has helped improve performance a great deal, but for the best gameplay with current and forthcoming titles, you need to consider sound cards with the following features:

• 3D audio support in the chipset. 3D audio means you'll be able to hear sounds appear to move toward you, away from you, and at various angles corresponding to what's happening onscreen. Microsoft's DirectX, version 9, includes support for 3D audio.

But you'll have faster 3D audio performance if you use an audio adapter with 3D support built in. DirectX 9 works along with proprietary 3D audio APIs, such as Creative's EAX and EAX 2.0, Sensaura's 3D Positional Audio, and the A3D technology from now-defunct Aureal.

• 3D sound acceleration. Sound cards using chipsets with this feature require very little CPU utilization, which speeds up overall gameplay. For best results, use a chipset that can accelerate a large number of 3D streams; otherwise, the CPU will be bogged down with managing 3D audio. This can slow down gameplay, particularly on systems with processors running under 1GHz or that are running at a high-resolution, high-color depth setting (1,024x768/32-bit).

• Game ports with support for force-feedback game controllers if your game controllers aren't USB compatible. If your games don't work properly with USB controllers, or your force-feedback game controllers use the game port only, check the game port features to make sure you'll feel as well as hear and see the action. Note that many recent game cards no longer include a game port or might use an additional slot for the game port connector.

Playing DVD Movies

You don't need a dedicated DVD player to enjoy the clarity, control, extra features, and excitement of DVD movies. DVD-ROM drives help bring the DVD movie experience to your PC, but having a DVD-ROM and a DVD movie player program is only part of what you need to bring the big screen to your desktop.

To get the most out of your desktop DVD experience, you need the following:

• DVD playback software that supports Dolby Digital 5.1 or better output. One of the best choices is Cyberlink's PowerDVD4.x, available from www.gocyberlink.com.

• An audio adapter that supports Dolby Digital input from the DVD drive and will output to Dolby Digital 5.1–compatible audio hardware. Some will remix Dolby 5.1 to work on four-speaker setups if you don't have Dolby 5.1 hardware or will accept S/PDIF AC3 (Dolby Surround) input designed for a four-speaker system.

Some can also pass through Dolby Digital audio to speakers that can perform the Dolby Digital 5.1 decoding. Some high-end audio adapters now support 6.1 and 7.1 speaker configurations; these also work with Dolby Digital 5.1 sound.

• Dolby Digital 5.1-compatible stereo receiver and speakers. Most high-end sound cards with Dolby Digital 5.1 support connection to analog-input Dolby Digital 5.1 receivers, but some, such as the Creative Labs Sound Blaster Live!, Audigy, and Audigy 2 Platinum series and the Hercules Digifire 7.1, Game Theater XP 7.1, and Fortissimo III 7.1 support digital-input speaker systems.

Depending on which types of speakers you are using and how they are attached, you might need to switch your mixer settings in Windows from analog to digital to hear sounds from your applications (movies, games, and so on).

Voice Dictation and Control

Some audio adapters are equipped with software capable of voice recognition that can be used to control some of your computer's operations. You also can get voice recognition for your current adapter in the form of add-on software. Voice recognition, as the name implies, is when your computer is "taught" to recognize spoken word forms and react to them.

Voice recognition products generally take two forms: those that are designed to provide a simple voice interface to basic computer functions and those that can accept vocal dictation and insert the spoken text into an application, such as a word processor. The minimum standard for most voice-recognition software is a Sound Blaster 16 or equivalent sound card.

Voice Command Software

The voice interface application is clearly the simpler of the two because the software has to recognize only a limited vocabulary of words. With this type of software, you can sit in front of your computer and say the words "file open" to access the menu in your active Windows application. For the average user, this type of application is of dubious value.

For a time, Compaq was shipping computers to corporate clients with a microphone and an application of this type at little or no additional cost. The phenomenon of dozens of users in an office talking to their computers was interesting, to say the least. The experiment resulted in virtually no increased productivity, a lot of wasted time as users experimented with the software, and noisier offices.

However, for users with physical handicaps that limit their ability to use a keyboard, this type of software can represent a whole new avenue of communication. For this reason alone, continued development of voice-recognition technology is essential.

Voice Dictation Software

The other type of voice-recognition software is far more complex. Converting standard speech into text is an extraordinarily difficult task, given the wide variation in human speech patterns. For this reason, nearly all software of this type (and some of the basic voice command applications, as well) must be "trained" to understand a particular user's voice.

You do this training by reading prepared text samples supplied with the software to the computer. Because the software knows what you're supposed to be saying beforehand, it can associate certain words with the manner in which you speak them.

Users' results with this type of application vary widely, probably due in no small part to their individual speech patterns. I've heard people rave about being able to dictate pages of text without touching the keyboard, whereas others claim that correcting the many typographical errors is more trouble than typing the text manually.

Sound Producers

Sound producers are people who intend to create their own sound files. These can range from casual business users recording low-fidelity voice annotations to professional musicians and MIDI maniacs. These users need an adapter that can perform as much of the audio processing as possible itself, so as not to place an additional burden on the system processor.

Adapters that use DSPs to perform compression and other tasks are highly recommended in this case. Musicians will certainly want an adapter with as many voices as possible and a wavetable synthesizer. Adapters with expandable memory arrays and the capability to create and modify custom wavetables are also preferable.

Many of the best sound cards for hardcore gamers also are suitable for sound producers by adding the appropriate sound-editing programs, such as Sound Forge, and by equipping the card with the appropriate connectors for SPDIF digital audio and MIDI interfaces. The latest Sound Blaster Audigy 2 Platinum and Platinum EX include internal (Platinum) and external (Platinum 2) breakout boxes with these features.

Hercules' Game Theater XP 7.1 also includes a breakout box. The Creative Labs Extigy provides features similar to those found on the Audigy 2 Platinum series, but it can be added to any system with a USB port. Most other audio cards designed for sound production features add jacks to the traditional trio of connectors on the rear card bracket.