Just came across this -- for the professional audio researcher:

http://www.audioresearchlabs.com/step_info.html

* Conforms to the folowing testing methodologies ITU-R Recommendations
o BS.1116 (small impairments)
o BS.1534 (medium impairments)
o BS.1294 (general testing requirements)
* Performs Two-comparison forced-choice tests with 5-point grading scale
* Supports training of subjects for all test methodologies
* "Evaluation" mode permits informal, fast and easy comparison of several systems
* Seamless switching between audio signals during presentation
* "Loop and Zoom" feature permits careful comparison of segments of audio signals
* Automatic randomization of presentation on a per-listener and per-signal basis
* Scoring window captures listener responses to file
* Subjective results can be loaded directly into a spreadsheet for data analysis
* Supports mono, stereo and 5.1 channel signals
* Supports 16, 24 and 32 bit word lengths
* Compatible with all sound cards that provide Windows DirectSound support
* Supports Microsoft WAV file format
* Easy to create session file controls all aspects of presentation

Interesting!

It appers that they (audioresearchlabs) have already done some subjective tests:

"Recently we prepared the test material and analyzed the results of a very large subjective quality test for next-generation 3GPP speech and audio codecs. We issued two reports, one for low bitrates (S4-040173) and another for high bitrates (S4-040172), which can be found here."

Are there any listening tests results for audio signals available to buy or even for free along with th audio files used by the human subjects? In other words Im looking for human subjective listening test results for audio signals along with the actual audio tracks used in the listening tests?

I would be indeed very cool to get the samples used in these 3GPP tests