Everyone today has heard of MP3, or more properly,
Layer 3. But way before MP3 became a household word, AT&T Bell
Labs Research was already working on even better audio coding technology.
PAC or Perceptual Audio Coding gave improvements above and beyond MP3
even back in 1994. By 1996, we had commercialized PAC for use in Digital
Radio Broadcasting, digital audio codecs over ISDN, and Internet Radio. With
the split of Bell Labs Research between AT&T and Lucent, PAC was also
split. Lucent kept the PAC name and recent patents, and developed PAC
into a proprietary product. AT&T kept key PAC personnel, and developed
PAC into the international MPEG-2 AAC
(Advanced Audio Coding) standard along with Fraunhofer, Dolby, and Sony.
The PAC logo in the upper right corner includes key elements: the AT&T
logo and musical items such as notes and a bass clef. If you're a musician,
you may think that the bass clef sign is backwards. You would be partially
right, as I intended it to suggest a bass clef which properly faces the left
like the number 9. But the sign is really the letter "P", and the following
bass clef notes are "A", and "C', which spells .. Aha! ... PAC!
Here's the logo redone using Illustrator. Click the image for a larger version.
NoBell Home - gjm
- last update 5/30/2002