Further research
# Research of the relationship between waveform degradation of an audio material and its auditory perception, http://soundexpert.org/articles/-/blogs/objective-difference-measurements-to-predict-listening-test-results-
# Research of accuracy/reliability of df-measurements.
# Use case for df-metric: comparison of resamplers.
# Use case for df-metric: comparison of headphones using HATS
2014 Sep. Development of the method for distortion visualization - diffrogram. The diffrograms are used, among other things, for presenting results of df-measurements on df-slides, http://soundexpert.org/articles/-/blogs/visualization-of-distortion
2011 Feb. Post-screening of grades in SE listening tests is developed and implemented, http://soundexpert.org/articles/-/blogs/post-screening-of-grades-in-se-listening-tests
2010 May. Development of precise time-warping algorithm, which makes it possible to use the new audio metric for testing analog audio equipment, http://soundexpert.org/articles/-/blogs/call-for-atrac-sp-type-r-test-recordings
2005 Aug. New SE listening test design with artifact amplification technology for testing high bitrate codecs, http://soundexpert.org/articles/-/blogs/new-version-of-soundexpert-testing-service-is-opened-for-beta-testing
2005 May. S Smirnoff, "DIFFERENCE LEVEL: An objective audio parameter", presented at the 118-th AES Convention in Barcelona, http://soundexpert.org/documents/10179/11017/DiffLevel_AES118.pdf
2001 Nov. Launch of SoundExpert project/website (SE) on soundexpert.info domain (+.org on 2009 Dec); after two months of beta testing first audio codecs were added to SE live listening tests - wma, mp3, mp3PRO, Liquid Audio, QDesign Music 2 and RealAudio 8, http://web.archive.org/web/*/http://www.soundexpert.info
2000 Apr. The first publication describing new audio parameter "Difference Level" (in Russian), Сергей Смирнов, "Измеряем качество цифрового звука ...", Звукорежиссер #4 2000