The goal of audio reproduction


I have followed the ongoing exchanges regarding subjective versus objective criteria for audio quality for some time now and finally wish to toss in my 2 cents. I am a Cognitive psychologist and have spent most of my professional life conducting research to measure how consumers and users of products perceive those products. I use formal psychological measurement techniques to quantify perceptions. In essence, I "objectify" subjective experience. So, the subjective versus objective distinction is, to me, somewhat misconceived. Given that perceptual experience can be measured (objectified), I would say the important question is, what physical features of products (i.e., physical audio metrics) correlate most accurately with perception? A more valid distinction, to me, is the distinction between "effective" (something of a causal nature) versus "affective" (i.e., something of an emotional nature). Objective product metrics "effect" subjective perceptions (affects). It's stimulus/response psychology.

I use multivariate statistical techniques to model effect/affect (i.e., stimulus/response) relationships. Here, it is important to consider that perception (i.e., affect) is not a single thing, but a composite of multiple factors. These include a) Valence (the standard good versus bad distinction, b) Potency (strong versus delicate feeling), c) Arousal (intense versus mild feeling) and d) Novelty (familiar versus unusual feeling). Hence, a complete description of perception requires a profile of these four perceptual components and not a single concept such as good or bad.

It is also important to note that perceptual data such as described above are obtained from samples of typical product users not from one, or a few, experts. Trained experts may be used in perceptual research, but their role is simply to describe the subtle perceptual qualities of products that may elude measurement. Experts serve as biological test instruments (very common in food, beverage, and cosmetics industries). But they don't serve as surrogates for typical consumers of products. For that, perceptual data are obtained from typical consumers. And those data are not expressed in terms of perceived physical properties of products, but the psychological responses to those physical properties.

The upshot of this for audio (it seems to me) is that if you just want to replicate a particular auditory event (e.g., a musical performance) then matching all physical metrics of the reproduced performance to the live performance is fine. But if you want to produce an enjoyable audio experience you might find that certain physical properties affect listener's perceptions more or less than others and that a departure from veridical presentation is preferred. For my part, I think that is fine. In fact, I am finding my tastes in audio quality are changing somewhat and I am now drawn to a slightly different quality in my system. I don't care if it matches the real performance exactly. I care that I like it.

jakleiss

Nice to see a scientist here. :)

You bring up a lot of the processes that are important in making certain claims about desirability, and that these are ultimately statistical not personal measures.

There’s a big difference between measuring THD+D and subjectively measuring listener preferences for different values and mixes of harmonic distortion as pleasurable/desirable or not. 

The work you describe IS science. Blindly taking a measure and claiming it ideal is not.

@jakleiss , this is an interesting approach. Have you considered segmenting the market of audio device consumers? I'll bet the research shows different preferences for each segment.

 

Yes, it is science. My professional career has been providing scientific evidence to inform product design, most recently in healthcare. The FDA requires scientific evidence to support any claims one may make about medical devices and treatments. That includes health benefits, but, also, such things and ease/safety of use and patient experience.