As mentioned before, I am no techie so I have used the words of others who understand the issues much better than I
"Brick-wall low-pass digital filters which are applied prior to DACs cause time smearing: Pre- and post- echos. It was the anedotal evidence that higher sampling rates sound better - time smearing is halved for a doubling of sampling frequency - that led to the view that it is the pre-echos which can lead to CD being accused of having a "glassy" or "harsh" sound. Meridian's apodizing filters all but eliminate pre-echos*. The post-echo smearing is no longer linear with frequency (like with the brick-wall filters), but the brain doesn't seem to mind this (echos being completely natural)."
and
"In the last decade, there have been tremendous strides taken in psychoacoustics and, importantly, neuroscience (which has informed the psychoacoustics). The short of it is that the industry has been grossly mistaken about the relative importance of the frequency domain vs. the time domain. Yes, there is the anecdotal evidence that higher sample rates are better, but no-one has ever really articulated why (other than the pre- and post-ringing "naturalness" arguments).
The latest findings, grounded in science, are that, when it comes to human hearing, the time domain is up to 5x more important than the frequency domain. If you hear a twig snap in the woods, you know immediately where it is (time domain); you actually “decode” what it was afterwards (frequency domain). This is evolution at work: hearing is the most important sense for survival: it works when your eyes are shut, when you’re not looking in the relevant direction, and in the dark.
The human hearing system is sensitive to about 10 microseconds in time resolution and here’s the kicker: much/most of this resolution is destroyed in anything encoded digitally below a 192kHz sampling rate.
That’s right: 96kHz is NOT enough.
However, is the public about to download or stream 192/24 audio? No, because it’s not *convenient*. How then to provide audio of the highest quality to the masses? The short of it is that Meridian has found a way of folding the time resolution information into a regular PCM file with a lower sample rate (it’s actually hidden below the noise floor). It’s a stroke of genius and means that MQA files appear to anything other than an MQA decoder as a playable PCM file. But an MQA decoder can "unfold" the file to the original sample rate, adding back the time resolution information.
Another crucial learning from neuroscience is that the brain has three times as many nerves sending signals TO the cochlea than sending information FROM the cochlea to the brain. This is a incredible fact; the brain actively switches the ear’s sensitivity (to frequency) depending on the situation (natural sounds, animal sounds, and speech). The encoding algorithm takes into account these different hearing modes (don’t ask me how!) and the "compression" applied to the master file (which can be anything from a (non-ideal) 44.1/16 master up to 8x sample rate) is not lossy in the conventional sense. There is nothing removed from the file that would allow a human being to differentiate between the MQA encoding and the master as heard in the studio. Lossy? No, that would be an extremely unfair and naive description. "Encoded for human hearing" would be more accurate.
So what is MQA? It stands for “Master Quality Authenticated”. Master Quality because it is able to deliver essentially what the recording artist heard in the studio. Authenticated because the audio data are signed (no, not DRM) so that an MQA decoder can verify the authenticity of the MQA file; that it is intact and as intended when it left the studio, having been signed off by the artist and producer."
The above may give you some clarification but I guess, (and it's only reasonable and logical ), that you will believe it when you hear it hence so if you get a chance go and have an audition of MQA