I know many of you have been waiting patiently for me to provide detailed, track by track results of the HD-Audio Challenge II. I’ve written in general terms about my findings but have not revealed a rigorous breakdown as promised. The reason is because I have submitted the abstract and description of my research project to the fall AES (Audio Engineering Society) Conference and will be submitting a paper to the the society’s Journal. One of the questions associated with the submission process asks whether I have already published the results of my survey. And while I have revealed the general process and some of my conclusions, the details of the survey have not yet been published. So I’m holding back. I apologize for the delay.<\/p>\n\n\n\n
Here’s the abstract that I submitted:<\/em><\/p>\n\n\n\n
Native High-Resolution versus Red Book Standard Audio: A Perceptual Discrimination Survey<\/strong><\/h4>\n\n\n\n
Mark Waldrep – (mwaldrep@csudh.edu) California State University, Dominguez Hills, CA, U.S.A.<\/em><\/p>\n\n\n\n
The perceptibility of high-resolution versus CD standard audio has been the subject of research and debate since the introduction of hi-res audio distribution formats almost twenty years ago. The author conducted a large scale survey to determine whether experienced listeners could differentiate between a diverse set of twenty native high-resolution PCM stereo recordings and downconversions of the same masters at CD spec, 44.1 kHz\/16-bits fidelity – Red Book Audio. Participants were encouraged to audition the files using their own systems, which ranged from modest, headphone-based personal setups to audiophile quality rooms costing in excess of $50,000 to professional studio environments. They were not allowed to use analytical tools or other non-listening means to assist in their observations. Over 450 responses were received from professional audio engineers, experienced audiophiles, casual music enthusiasts, and novices aged eleven to eighty years. The online survey submissions show that high-resolution audio was undetectable by a substantial majority of the respondents regardless of experience level, equipment cost, or process with almost 25% choosing \u201cNo Choice.\u201d However, some evidence suggests specific genres and recordings produced marginally higher positives.<\/p>\n\n\n\n
We’ll see if the society accepts my submission. I’ll keep you posted. I did get some feedback from an AES member complaining that my study doesn’t meet rigorous standards. This individual stated: <\/p>\n\n\n\n
“From what I see in a quick look at Mark Waldrep’s website about this survey, little in it appears to qualify as valid test methodology.<\/strong> Random hardware, random acoustics, random listeners, listening test protocol apparently left up to the listener (duration, repeats, internal references, loudness). There are reasons why these variables are controlled in formal testing before statistical analysis can have any validity. A full discussion of methodology for high res audio testing is too long for fb but there are publications at AES showing high res audibility when done with appropriately careful design.”<\/em><\/p>\n\n\n\n
The listing of “Random hardware, random acoustics, random listeners, listening test protocol apparently left up to the listener (duration, repeats, internal references, loudness) sounds like the real world to me. What good is “formal testing” if it doesn’t reflect the real world?<\/p>\n\n\n\n
I responded:<\/p>\n\n\n\n
“I have never stated that my survey qualifies as a ‘rigorous’ study. The industry makes the claim to real world listeners\/audiophiles that “hi-res audio” makes a “dramatic improvement” in fidelity. Virtually all of the recordings available on disc, as downloads, ,and streams labeled “hi-res audio” are in fact standard-resolution masters digitized at hi-res specs without any fidelity improvement. My survey used real high-resolution recordings. Almost 500 respondents in real world (their own systems) circumstances failed to beat chance in selecting the high-resolution version over a CD downconversion. And just over 25% stated they couldn’t hear any difference. While it may not be as scientifically rigorous as having seven twenty-year olds listening to loud noise bursts in an anechoic chamber and claim to hear differences between 192 kHz and 44.1 kHz, I think my survey contributes in a meaningful way to the discussion. I hope you agree.<\/em>“<\/p>\n\n\n\n
I expect some criticism but am optimistic that there is value in the survey. Recall that the Meyer and Moran AES paper used random home systems, members of the Boston Audio Society, and non rigorous methods. We’ll see.<\/p>\n\n\n\n
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