Can you identify the artifacts of lossy audio coding? The second edition of AES’s acclaimed educational and artifact discernment training tool, Perceptual Audio Coders: What to Listen For, has been released as an enhanced online resource for free access either as an online experience or for download for offline use.
The 2021 Web Edition includes updates of the perceptual audio coding tutorial content and specific audio examples that were features of the CD-ROM edition introduced in 2001. The 20th anniversary update also includes new material on advanced coding strategies – some accompanied by interactive displays, an enhancement applied also to select first edition elements. The content can be seamlessly and conveniently played back natively on both computers and mobile devices.
The AES Technical Council project second edition introduction by Jürgen Herre and Schuyler Quackenbush, cochairs of the AES Technical Committee on Coding of Audio Signals (TC-CAS) describes the history and scope of the project:
“Compared to other ‘classic’ disciplines in audio engineering, the field of perceptual audio coding is a rather comparably young technology, combining elements from digital signal processing, coding theory, and psychoacoustics into one system. It is, however, mostly the psychoacoustics that frequently leads to questions from nonexperts (‘How does that work?’) and sometimes is even perceived as some kind of ‘black magic’ within the coder. Since many of the members of the AES Technical Committee on Coding of Audio Signals have been confronted with such questions, the idea of an educational publication on this topic soon found broad support within the group once its concept was formulated.
“It was Markus Erne who originally proposed the production of a CD-ROM that would offer non-experts some guidance on the background and sound of the perceptual effects a listener is likely to be confronted with when working with compressed audio signals. Initiated at a Technical Committee meeting at the AES 106th Convention in Munich in 1999, the idea eventually took more than two years and quite a number of Technical Committee meetings to be fully developed and implemented within the committee, finally leading to its publication.
“After successful sale of several print generations of the original CD ROMs by the AES, the Technical Committee on Audio Coding felt that it was time for an update to include new coding strategies that have become popular since the first-generation CD ROM release. This second-generation material features a number of enhancements that the Technical Committee felt were useful and timely to increase its attractivity.”
A brief Web Edition project introduction is publicly available on the AES YouTube channel.
A detailed introduction of the second edition project was presented during the 150th AES Convention in the spring of 2021 by Herre, Web Edition editor Sascha Dick and TC-CAS Committee member Christof Faller. That presentation can be viewed by members in the AES Live: Videos portal.