In MS Windows, you may see unexplained references to something called "High Definition Audio" ... usually in the context of system devices.
Basically, all of these references are just referring to ON-BOARD AUDIO hardware and the associated drivers. In other words, the Audio ports that come as part of the PC, as opposed to Audio hardware that is inserted as a PC card (PCI card-- the most common 'Audio Card' is the Audigy Sound Blaster card).
High Definition Audio ("HD Audio") is essentially a marketing term created by Intel.
It refers to the fact that there is a specification in place that allows PC and system board manufacturers to create a standardized "next generation" PC audio interface. "HD Audio" replaces the previous generation of sound ports (audio out, mic in, etc) which are referred to as "AC'97".
From the Intel Website:
Intel HD Audio hardware is capable of delivering the support and sound quality for up to eight channels at 192 kHz/32-bit quality, while the AC‘97 specification can only support six channels at 48 kHz/20-bit. In addition, Intel HD Audio is architected to prevent the occasional glitches or pops that other audio solutions can have by providing dedicated system bandwidth for critical audio functions. [The need for 'dedicated system bandwidth' for audio, and how it might prevent "pops", is not clear; esp. since proper implementation and optimization of the existing AC'97 standard would accomplish the same thing. - Editor]
Considering that 6-channel sound is beyond the hardware setup of the vast, vast majority of worldwide PC users, and that 48 kHz sound (the same frequency used for Audio CDs and audio in DVDs) is the highest quality used by most people for audio, saying "only" in the text above ("AC'97 can only provide six channels ... [i.e. 5.1 Stereo]") is really pushing the marketing spin...
The good news about "HD Audio" is that it provides a way for most PC users to get higher-quality audio experiences without having to spend additional money on a fancy Audigy audio card! As PCs have more than enough power to provide better software audio encoding/decoding than is available in most consumer level audio equiptment, raising the bar for the Audio standard was over-due...
content added : November 21 2007 Author: attributed to ' Liberty Miller '
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