The Challenges of Digital Audio (Part 1)
By Alan Ruberg, Systems Architect
Oftentimes, we analog humans expect all things digital to be perfect. In reality, digital devices are far from perfect machines. Nowadays, electronic designs have become so sophisticated, even computer components contain defenses against errors. Engineers work day and night to obtain the highest performance, maintain quality, provide value, while keeping manufacturing costs down. The results of this effort are 500 channels of high definition TV, terabyte hard drives, gigabit networking, and mobile phones with LTE technology.
To perform these “miracles,” trade-offs are made between, space, speed, and/or accuracy. For the example of hard disks, accuracy is the most important. Time is sacrificed by occasionally repeating reads and writes. Space is sacrificed by storing somewhat more data than necessary. In relation to CPU and memory speeds, hard drives have always been very slow. That’s why you keep having to go and buy more memory (or a new computer!).
Networking is inherently slow, especially wireless where all communications share the same air space. Network speeds keep improving and that’s thanks to making the right tradeoffs and assumptions. For computer networks, accuracy is still most important, but everyone wants faster web browsing and file transfers. Errors are handled much the same as hard disks: add a little bit more data to detect or correct errors, and then repeat when things go wrong. Repeating happens infrequently enough that we barely notice, well most of the time; I’m sure you’ve seen surprisingly slow software updates, hung web pages, and servers not responding! Things get worse when you’re sharing a network (or radio frequency) with your neighbors.
Most of us analog humans know we aren’t perfect. It’s true, but we are also very picky. People are very sensitive to time and speed and expect things to proceed smoothly. A football isn’t supposed to stop in mid-flight — even for a moment. Any skip in a song or broken syllable on a phone conversation sticks out like a sore thumb. Even if the note or word comes out, it’s at least as annoying when there is noise or it’s the slightest bit late. Sound must be free of even miniscule gaps, skips, trips, jitters, and repeats. Gaps in data communication must be corrected:
Computers are designed to have error correction to fix stalls or gaps in data, as depicted in the above comic. Stay tuned for Part 2 of The Challenges of Digital Audio, when we explain how WiSA technology handles error correction