A difference doesn’t have to be audible to matter

A common view among scientifically-oriented audiophiles is that controlled, double blind listening tests are equivalent to objective measurements. Such people may be further subdivided into those who believe that ‘preference’ is a genuine indicator of what matters, and those who believe that only ‘difference’ can count as real science in listening tests.

I can think of many, many, philosophical objections to the whole notion of assuming that listening tests are ‘scientific’, but just concentrating on that supposedly rigorous idea of ‘difference’ being scientific, we might suggest the following analogy:

Suppose there is a scene in a film that shows a thousand birds wheeling over a landscape. The emotional response is to see the scene as ‘magnificent’. In this case, the ‘magnificence’ stems from the complexity; the order emerging out of what looks like chaos; the amazing spectacle of so many similar creatures in one place. It would be reasonable, perhaps, to suggest that the ‘magnificence’ is more-or-less proportional to the number of birds.

Well, suppose we wish to stream that scene over the internet in high definition. The bandwidth required to do this would be prohibitive so we feed it into a lossy compression algorithm. One of the things it does is to remove noise and grain, and it finds the birds to be quite noise-like. So it removes a few of them, or fuses a few of them together into a single ‘blob’. Would the viewer identify the difference?

I suggest not. Within such complexity, they might only be able to see it if you pointed it out to them, and even after they knew where to look they might not see it the next time. But the ‘magnificence’ would have been diminished nevertheless. By turning up the compression ratio, we might remove more and more of the birds.

This sensation of ‘magnificence’ is not something you can put into words, and it is not something you are consciously aware of. But in this case, it would be reasonable to suggest that the ‘magnificence’ was being reduced progressively. The complexity would be such that the viewer wouldn’t consciously see the difference when asked to spot it, but clearly the emotional impact would be being reduced/altered.

For all their pretensions to scientific rigour, double blind listening tests are fundamentally failing in what they purport to do. They can only access the listener’s conscious perception, while the main aim of listening to music is to affect the subconscious. Defects in audio hardware (distortion, non-flat frequency response, phase shifts, etc.) all tend to blur the separation between individual sources and in so doing reduce the complexity of what we are hearing – it becomes a flavoured paste rather than maintaining its original granularity and texture, but we cannot necessarily hear the difference consciously. Nevertheless, we can work out rationally that complexity is one of the things that the we respond to emotionally. So even though we cannot hear a difference, the emotional impact is being affected, anyway.