At this point in time, Soundbooth ASND files cannot be imported into Audition CS 5.5. The individual clips and the rendered mixdown preview can be extracted from existing ASND files by changing the extension to .ZIP and unzipping the contents. Each clip is located inside a GUID-encoded subdirectory, and the Mixdown.wav file in the root is the latest complete mixdown of the multitrack or edited audio file.
We are still exploring possible import scenarios for legacy Soundbooth project support for Audition CS.
I tried your .zip tip, but it wouldn't uncompress with the builtin Archive Utility.app in OS X 10.6.8, nor would commandline unzip or /usr/bin/file even recognize it as a zip archive. After ripping the arms off of a couple of teddy bears, which also didn't help, I installed The Unarchiver, which worked.
But, holy crap, what a colossal waste of teddy bears that was. Took a while, too.
I have recently upgraded "Production Premium CS4" to "Production Premium CS 5.5."
What. A. Huge. Disappointment. Regarding this issue.
Upgrading Adobe products has always improved productivity/workflow for my production department. And that has always been my thought paradigm associated with all Adobe products. Please notice the use of past tense.
Now I have to thoroughly research Adobe products when considering upgrading in the future. In the past, when Avid dropped the ball adapting to the needs of NLE people, Adobe seemed to pick it up and run like Forrest Gump. What happened Adobe?
I fully agree with hhprod2: some of us did rely on the soundbooth workflow and the asnd file features. The most important one for me is that asnd files keep the rack effects along with the audio: it allows tweaking the effects later within Soundbooth (but other Adobe softwares would read the mixed/bounced/baked/effects applied version directly: the famous "Mixdown.wav" file that _durin_ mentionned in its previous post).
So, not having a backward compatibility for Adobe Sound (.asnd) files in Audition CS 5.5. is awkward (even if it was probably not trivial to implement).
But let's not be too pessimistic and hope Adobe will assume the issue by allowing asnd files to be opened in the arriving Audition CS6!
This for me was what layers are to Ps. Seems like CS6 can't do it either.
Pr and Ae CS6 can still understand .asnd files.
If you drop your asnd file onto the Pr timeline and then right-click and Edit in Au, it extracts the .wav file in Au for you. It's all one waveform though, so no separate tracks.
My tests with Ae have not been as successful.