Is High Definition Music Actually Better?

There's an ongoing argument as to whether it's worthwhile collecting or playing FLAC music at resolutions higher than typical of CD. Some people swear by it, say it produces better sound, and others say they are experiencing placebo. This argument has gone on for some time, and perhaps we'll see some more of it in the comments. 

Compression

So there are a few elements to this which I'll go through. The first is the issue of compression. There is a detectable and provable difference between compressed files like mp3 and FLAC files. At least at rates below 320kpbs, people can generally tell the difference between FLAC and mp3.

These are reasonably subtle differences that a trained ear is more inclined to pick up. The attack of drum sounds is punchier. There are more details and nuance at the high end in particular. You can strongly hear the difference between a more heavily compressed song and a lossless one, if it's a simple acoustic recording, with dynamic range, in an acoustic space, because it has a lot of nuance at the high end. An example might be a concert piano in an auditorium. In general, in my experience, songs with more 'dynamic range' benefit most from the format.  

Loudness Wars

The other issue is another kind of compression. Not the data saving kind. There's an audio process that's applied to almost all modern music that makes the quiet parts of the song louder so that everything is more or less equal volume. This is what they use to make ads louder on old-school broadcast TV. It's not technically actually louder; it's just that everything in the mix is equally loud. Dance and pop music is often drenched in the stuff. 

Sites that sell vinyl or high definition music tend to use earlier studio mixes of the song. In fact, HiDef music sites actually seek out the earliest studio mixes. These mixes have more "dynamic range", that is, there is more variation in the volume of various parts. This produces a sound that has more nuance, and subtlety than the typical radio or album mixes one might buy.

The Actual High Definition Part

So far we've dealt with two ways, high definition FLAC files are objectively different, but they have nothing to do with the actual resolution. Let's be entirely clear about this part: You need a high-resolution DAC (or digital to audio converter), speakers that can reproduce ultrasonic and subsonic sounds, and even then, you cannot actually hear sounds above and below a certain point. But, there are recent studies showing that ultrasonic sound does improve the perception of listenability, and reduce listening fatigue, despite no one actually being able to hear it.

Similar studies also show there are differences in brain region activation especially when subsonic and ultrasonic sound is present at the same time (but also to a lesser degree with ultrasonic sound alone).

It's hard to speculate how this works. It could be the way the inaudible sound interacts with the audible sound. However, I suspect it might be mainly something we can unconsciously perceive but the auditory processes of the brain filter out. Hence why there are differences in brain activity. 

That is to say, I think, our brain is aware of it unconsciously, but we don't hear it consciously. As the study into ultrasonic sound suggests we are left with a vague sense of "this is pleasant". Which is likely why AB testing is never able to pick much up. This may connect to why ADSR works with what appear to be mostly high pitch sounds, like crumpling, and tinkling sounds. Whatever the case, it does appear as if ultrasonic sound can actually make music subjectively more 'pleasant', even if no one could accurately 100 of the time or even most of the time; detect the difference between the two. An area that certainly needs more study.

Keep in mind; you're going to need not only a high-resolution DAC, but high-quality speakers to produce ultrasonic sound, and very large bass drivers to produce subsonic sound. It appears as if the former is more important for subjective "niceness" but high definition is going to be superior is for large bass bin setups for gigs and dance parties. On that scale, the subsonic sound is going to be quite detectable through the body/feet. More detectable than any ultrasonic sound. Either way, you're going to need to outlay a fair bit of money before you're going to be able to benefit from inaudible sound ranges.

Conclusion

So is HD FLAC music better? Definitely at least because of the lack of compression, and higher dynamic range mixes used for the files. That said if a person loves heavily compressed (in both senses) sound, they may prefer mp3s. But for audiophile types, generally, there's a benefit. File compression aside, like records; this may be mainly due to mixing, rather than the format. However, cautiously I'll state that there is science to suggest that music with inaudible components is actually superior if for no other reason than reduced listening fatigue. Whilst we have science to suggest this, we have no idea how this actually works (both decreasing fatigue, and increasing positive listening experiences whilst making measurable changes to brain activity) 

I'd say the jury is still out there, but it's not exactly according to science placebo. Incredibly subtle perhaps. Because of the associated expense as with vinyl fans, unless you already have a decent speaker set up you might not bother unless you are just after those sweet early mixes. And I feel like everyone who's really into music should check out those.

To my ears, it sounds sweeter. Not just the mix, or the lack of file compression, but something....almost extrasensory. I'll let the audiophiles judge for themselves.