155 comments

[ 2.7 ms ] story [ 194 ms ] thread
Interesting, whenever I failed it was between 320kbps and uncompressed wav. I know that I did a blind test about 10 years ago and could distinguish between ~192kbps variable bitrate and lossless audio with my left ear, mostly influenced by percussion (left ear for some reason can hear 21kHz frequencies).
Uncompressed CD audio is 1.4 Mbps. FLAC can do roughly 2:1 compression, so that's 700 kbps. It's not crazy that modern mp3s (encoders have gotten better over the years) sound good at half the size of something lossless. They're only removing subtle details at that point.

You can see the same thing with high-quality JPEGs vs PNGs for photos. There's a decent size reduction, but to see the difference, I have to open the files in Photoshop, zoom in, and toggle which one is visible. If I compute the difference in Photoshop, it's usually only a few levels different, and never more than ~8. That's really hard to see.

Sadly, they're not even using a modern codec like Vorbis or Opus.

That said, while I doubt I can tell the difference between FLAC and high-quality Vorbis, once I learned to listen for distortions on the high end, it's a little hard to unhear. Same as looking for blocking artifacts in JPEGs or video.

FLAC is lossless, and given a random piece of audio it would be impossible to always encode into 700kbps something that is originally 1.4Mbps without loss of information. So your 2:1 samples claim doesn't sound accurate. Maybe file size, but not sample count.
Yes, if you are encoding level-maximized white noise, FLAC cannot compress at that ratio, or likely at all.

Music is not white noise. It does not maximize the channel capacity of the audio spectrum. As a rule of thumb, FLAC compresses most anything a human might call "music" in about a 2:1 file size ratio.

Right, so file size, not sample count. It's lossless.
It's the sibilance that always gives it away for me. Even the 128kbps mp3 sounded fine for most of these, but when it fails, it really fails.
Wow I kept picking the 128kbps MP3. Im using Sennheiser HD58X. I'm plugged into the headphone jack of my Desktop monitor which itself is getting audio via USB-C. Maybe the amp is bad in the monitor? Wonder if an external DAC would be any better.
That's the road you walk down to $10,000 audiophile RCA cables.

A man sits on a weight bench, wondering if the equipment is defective because he can't seem to bench press 800 lb...

I think in this case it's more like you've bought a truck but you put a lawnmower engine in it.

It's a big step between esoterics and "please don't use the cheap shitty DAC that was integrated into your monitor to satisfy a feature checklist".

The amp part will matter a lot the more impedance the cans have, and many of the better headphones are high(er)-impedance. Might as well spring for a headphone amp + DAC combo just to see how it sounds. It's not that expensive, FiiO has some for under 80 bucks, for example.

If you keep picking the 128kbps track it does mean that you can hear a difference, and maybe that you subjectively prefer the more compressed audio.

That's why usually good audio tests use ABX where it's not about seeing if you can identify what is best, but rather if you can identify a difference at all. See for instance: http://abx.digitalfeed.net/

EDIT: I actually just tried the test and... ended up doing the same thing you did. On the Neil Young track I could hear a definite difference in the high pitched violin-like background, but I ended up selecting the 128kbps track as the "highest quality", maybe because the compression made it sound smoother.

high end consumer audio is largely snake oil
Which is why you should purchase studio equipment.
I do. I'm very pleased with the (relatively) flat response using powered studio monitors in my home theatre setup, which are (relatively) affordable compared to something with similar performance purchased from a hi-fi specialist.
Either that or you've been conditioned to like the compressed sound. Or maybe your ears are not what they used to be?
(comment deleted)
The sound from my monitor (DisplayPort) is definitely not as good as what comes directly from my PC, even without a DAC

The Apple USB-C to 3.5mm doesn't break the bank, works with Windows fine and the headphone nerds seem to rate it

Here's one way to think of it: spend money on audio gear until you can't hear the difference, or until you run out of money.

If you can't hear the difference at a low price point, that's not a curse, it's a blessing.

> Maybe the amp is bad in the monitor?

Yeah the AMP and the DAC.

The HD58X uses 150-ohm drivers. These can be used without an amplifier just fine, but detail will be lost and they'll be quieter. My general rule is anything 80ohm and over will want an amp... You DEFINITELY want an external DAC+amp for those 58X's.

The DAC chip in a monitor will be the absolute cheapest one they can source, and is probably receiving a lot of noise from the monitor itself as well. The good news is that you don't need to break the bank to get something decent; a budget of ~$100 will get you something a million times better than a screen could ever deliver.

Which DAC do you recommend?
When I was in the mark for a decent DAC last year, I settled on JDS Atom DAC. Cost $100 I believe and seems like their support is good. Though I don't have anything else to compare, it seems good so far.
JDS Labs are the very definition of bullshit-free top-tier stuff. You chose well.
I'm going to confine myself to DAC+ Amp devices here. The main trick to suss out audiophile-snakeoil is checking the specs to see what the Total Harmonic Distortion is when the volume is maxed out (ie, before the signal starts clipping). THD is easy to have low (<0.01) when there's little load. With amplifiers of all kinds, quality is determined by how low the THD is when it's turned up. If it's >1% then it's poo, if it's ~0.1% then it's okay, if it's 0.01% or less then it's pretty good.

The $400 Element II [1] from JDS Labs (makers of the legendary Objective-2, a DAC+Amp that was designed to give top-end performance at bottom-end prices) is very literally as good as it gets without snakeoil entering the equation. THD when under a 150-ohm load is 0.0008%. That's very good. This is what I'll be upgrading to if my setup at work ever dies.

My work rig is an Aune T1 [2] which retails for $250 but Massdrop does them for $100-$150 sometimes. Yeah it's a "tube" but that doesn't matter as much as myth would have you; today's tubes are pretty transparent unless you deliberately get something that isn't. THD is good however nowhere near JDS Labs-level of perfection.

The Fiio Q2 mk2 [3] can be found for as little as $100 and it's a solid performer, though I haven't personally used it, Fiio's reputation is impeccable.

[1] https://jdslabs.com/product/element-ii/

[2] https://www.amazon.com/Aune-Second-Generation-Amplifier-Deco...

[3] https://fiio.com/newsinfo/53025.html?templateId=1133604

In addition to headphones, and hearing, there is also training.

There are a number of audio artifacts in MP3s that are much more noticeable after training. However, many of them become much less discernable with variable compression rates and lower compression (>256kbps). It's possible to train on those artifacts, but I've always avoided it since I don't want the "projectionist effect" of making standard recordings less enjoyable.

This is not the case for many audiophiles. They want to fix all the bugs!

What is the projectionist effect out of curiosity?
As I understand it from the context - if you make yourself able to find flaws, you'll constantly find them, or think you have found them.

If it's something you love, it may make it your enjoyment a bit less.

For me, it's why I don't watch my wife pop zits in the bathroom. It's nice to not know about those flaws. :)

Projectionists needed to learn to spot the little white blobs in the corner of films so that they could switch reels. Once trained, you can basically never miss it and it will annoy you every time you see it. Also, if you develop visual compression schemes (e.g. MPEG, H264, etc) you will basically always see the blocking artifacts and chroma aberration in compressed video. That leaves you hating all DVDs, blueray, and digitally compressed video since looking at it becomes work.
>you will basically always see the blocking artifacts and chroma aberration in compressed video

Netflix is AMAZINGLY low quality, even on the higher-quality tiers, and working with compressed video was one of the factors that ultimately led to me cancelling my subscription - I'd rather pay (or yarr) for an actual copy rather than something that's almost more compression-artifacts than actual video.

(comment deleted)
This is so VERY true, many years ago while working for an audio company I went along to ETH and met some researchers working on video compression.

Once you've been shown the effects of overly strong video compression it is really hard not to spot them everywhere.

Not to mention TV post-digitalization. Nowadays one can't watch TV or streamed videos without getting annoyed over how poor trees, bodies of water or audiences in arenas look due to the compression artefacts. Ironically, I prefer buying a DVD for a few € to streaming a movie simply because there's less visible artefacts.
>I prefer buying a DVD

DVDs are horrible quality though. Compression everywhere and low resolution. The streaming services that I've watched are all better than DVD, at least 720p.

If compared to DVB-T with far to low bitrates, or streaming over crappy Internet connections, DVD's are far better in comparison.

Blu-ray is obviously the better option, but they're more expansive and not always available, especially when it comes to stuff that isn't produced in the U.S.

I got 4/6 with a pair of Takstar Pro 82's (nothing special) connected over HDMI from my monitor.

I missed Neil Young and, surprisingly, the classical music, although I suppose that classical music is used extensively when testing codecs.

Curiously I picked 320kbps all but one occasion. Perhaps all those years of listening to MP3s have conditioned me to prefer the MP3s?
How is this still a debate? Just keep a .wav backup and convert it to modern formats as they come. At this point I can only assume people listening to actual mp3's pirated the songs.
Or they use a streaming service, such as Spotify, etc.
Well high-quality (read: normal-quality) streams are a premium option. The more tech-enthusiastic might self-host a plex server or something similar.
You can assume, but it would be a pretty dumb assumption.
A worthless experiment. Audio is only as good as the weakest link. All phones will be insufficient for this test. All computer jacks and all monitor jacks will be insufficient. Most headphones will be insufficient.

Only upon using a dedicated headphone amplifier with a moderately good pair of headphones should the answers become easy.

Isn't that kind of the point of this being posted? It shows that you don't really need lossless audio on your phone if you need special equipment and an otherwise silent room to tell the difference.
I took the test several months ago with my nice DAC/amp headphones and got 5/6. Just tried again on my phone and got 0/6. And at the end it asks you what you were using.

Seems to me like the experiment has value.

I often see claims like this from audiophiles yet the research with AB tests has generally found that no such differences actually exist.

https://hometheaterreview.com/why-do-audiophiles-fear-abx-te...

That may be true for sources and amplifiers, but not for speakers/headphones.

Go to any audio store with speaker rows and listen to a few. They are hugely different, and none of them are cheap quality.

Which basically means that we are far from solving the accurate speaker problem.

There are also cases where the differences in amplifiers are obvious - for example some headphone/amplifier combinations have issues with low frequency response (related to impedance IIRC)
Genelec/Revel/Kef beg to differ. You can measure speakers and there are a fair few accurate ones out there.

The problem that we are far from solving is the problem of people buying inaccurate speakers.

The last part of the quiz literally tells people this.
i'm sitting in front of a 3.5k playback system, decent room, and i produce music for a living and i work in a lossless daw every day, and i did horribly :(
That kind of proves the point of the test?

128kbps on nice headphones will always sound better than WAV on garbage headphones.

A few pieces were easy to identify even with a phone and regular headphones. I tried a Pixel 4a directly to Philips SHP9500 and got 4/6.
I didn't notice any difference between the three files in any of the cases...and that leads me to question:

Can we verify that the website choices are in fact legit? i.e. the 320k mp3 is in fact 320k and the uncompressed wav is in fact that. And also, that the browser isn't messing with the choices either (by e.g. caching the first file you play and reusing it for the other choices).

Also, I ordered an optical cable so I can use my amplifier's DAC rather than the onboard soundcard DAC.

3/6 they all sounded exactly the same to me. I just guessed.
I picked 4 out of 6 and never picked 128kbps. I am pretty sure I can reliably weed out 128Kbps, but WAV vs 320Kbps is more or less luck. Jay-Z was the easiest as the chiptune sample is a rectangular wave and hence has a very high frequency component that actually makes sound less palatable, not more. "Hissiness" of strings helps on classical and Neil Young, but pop music (Katy Perry and Coldplay) with its flat wall of sound is much harder - I was listening for "z"s and "s"s and high hats. Acapella (Suzanne Vega) was the hardest for me and I think I just lucked out.
Same results.

I'd love to see a similar experiment with newer codecs like Opus.

Suzanne Vega ought to be the hardest thing in the world to find an MP3 artifact in, since "Tom's Diner" was the primary litmus test used in the development of the psychoacoustical model.

https://en.wikipedia.org/wiki/Tom%27s_Diner#The_%22Mother_of...

I also found that really hard, and now I know why - that's amazing!
Great. I was feeling good about myself for managing to pick the uncompressed one, and now I keep wondering if I just got lucky. :D
I'd argue the opposite, "voice is the hardest to get right so we chose a vocal track" -> voice is hard to get right, so they got it least right.. For me, Tom's Diner was the easiest of the lot to pick out.
I was the opposite. The classical was easiest because it had so much texture that was easier to spot tiny flaws in that texture.
Can you explain what exactly "texture" means here?
At any point, there are many different types of instrument playing a variety of pitches and melodies.
I have a similar experience with being easily able to distinguish between uncompressed and 320kbps MP3s with certain kinds of music. Music with a lot of emotion in the singer’s voice or with both instruments and singers spread over a large area (Bollywood music from the late 90s) are easier to distinguish. Of course, I tested this with two different streaming services, so it may just be differently processed files. Modern pop songs on the other hand sounds the same to me irrespective of the level of compression.
I did the quiz once and also got 4/6. I alternated through all the samples around 4 times before making each choice. I messed up on the only two where I felt baffled by the choices, so at least I know what I don't know. :-)

I chose the 320 kb/s for Katy Perry but was vacillating between that and the actual WAV. The one I completely screwed up was Jay-Z where I picked 128 kb/s. However, I knew I was lost with so much electronic glitching and distortion. While I heard differences, I had no idea what was a compression artifact versus a synthesis/mixing artifact. I also had no prior listening experience for either of these two, so no preconception for how it should sound.

For the other recordings, I think I could hear the masking of the psychoaccoustic models. Essentially, in the WAV I heard a "fuller" mix with overlapping sounds, while in the compressed versions I heard dropouts where a dominant sound was present in what felt like isolation. For Suzanne Vega this wasn't so easy, but I felt her voice and the reverb were more clear and natural in the WAV.

This was just with my old Sony MDR-NC22 noise canceling ear buds driven by my Thinkpad audio jack. My idea of a hi-fi environment is a Yamaha receiver and reasonable tower speakers like my Polks.

I got 5/6 with a Schiit Magni/Modi stack and Beyerdynamic DT 770s.

On the flip side of the coin, my wife regularly listens to music just out of her phone speaker and claims to not notice the difference.

Everyone enjoys music in a different way, and I'm glad there are plenty of options!

Doesn't it depend on decoder used by your browser? Will these sound different if downloaded and player with a music player software?

Difference is too hard to notice in voice only audio example because it does not have that variation/detail in it anyway.

Decoders are supposed to be bit for bit identical. It's the encoders which are different.
If you are referring to the Tom’s Diner clip, I actually preferred what the 320 mp3 did to the vocal reverb, its a little more stereo/wobbly than in the uncompressed.
I got 6/6, you can select the right question based on how long it takes to start playing audio initially :)
You must be a security researcher specializing in side channel attacks.
Well now I can’t take this test and trust the results.
Maybe you can run through all the samples to cache them in your browser. Reload the page to randomize then take the test.
Music is engineered to sound good on every quality, up until the point when it is heard on low quality devices and adjusted so it is still perfect. It causes finding differences so difficult. It is not only that compression is so good, or that we don't hear the difference. It is also about the music being made in a way we shouldn't hear it.

This test result is a tribute to sound engineers who make music good on every device.

This kind of test is really tricky because you are either trained to recognize the artifacts of MP3 compression, or you are not in which case you just "trust your gut". And if you are used to listen to compressed music (e.g. youtube), you will probably pick that.

And that is not even taking into account that MP3 (despite being really old and not the most efficient at this point) is good at what it does, especially at 320k.

Usually what newer codecs buy you is the same quality for lower bitrates. AAC-HE, for example, would be pretty hard to pick out at 128K. Opus at 96K. Push either of those to 320K and I doubt anyone can really tell the difference.

A similar thing happens with MPEG2. At a certain point, all the bits thrown at it make it indistinguishable from source. Where newer codec shine is when you start saying "what if we do this at 1000kbps" or "600kbps".

https://opus-codec.org/examples/

This makes me wonder—these discussions usually assume that compression artifacts make audio sound worse, but is that always necessarily the case? Could they just as easily make it more pleasing?
I expect removal of very high and low frequencies could make some music sound subjectively better.
Sometimes it may be helpful to look at some fundamentals from a completely analog point of view before trying to make the most out of what digital has to offer.

If so Chapter 14 Fidelity and Distortion in Radiotron (RDH4) can be a good place to start:

https://ia801602.us.archive.org/18/items/bitsavers_rcaRadiot...

>The values of total harmonic distortion to provide objectionable distortion are 2 % with a frequency range of 15000 c/s and 10.8% with a frequency range of 3750 c/s for music, and 3% and 12.8% respectively for speech, with a pentode.

Even if almost nobody is using pentodes any more, you could do worse.

The whole thing is 1400 pages, you can see what engineers were up to with their slide rules back then.

Chapter 19 if you really want to know about decibels . . .

With THD, strong odd harmonics are objectionable sooner than the even ones, unless you happen to like an aggressive over-driven transistor sound.
They certainly can, it really depends on the music being compressed and the user’s preferences. MP3 often sounds "cleaner" thanks to shaving off part of the spectrum that is not as audible.
I imagine that by now, skilled audio engineers who are working on distribution tracks for artists will well and truly have the hang of mixing for the various lossy codecs out there.
It sounds like most "engineers" these days just put a brickwall limiter on the master and call it a day.
(comment deleted)
“Whatever you now find weird, ugly, uncomfortable and nasty about a new medium will surely become its signature. CD distortion, the jitteriness of digital video, the crap sound of 8-bit - all of these will be cherished and emulated as soon as they can be avoided. It’s the sound of failure: so much modern art is the sound of things going out of control, of a medium pushing to its limits and breaking apart. The distorted guitar sound is the sound of something too loud for the medium supposed to carry it. The blues singer with the cracked voice is the sound of an emotional cry too powerful for the throat that releases it. The excitement of grainy film, of bleached-out black and white, is the excitement of witnessing events too momentous for the medium assigned to record them.”

― Brian Eno, A Year With Swollen Appendices

Apparently yes:

http://web.archive.org/web/20090303092253/http://radar.oreil...

Personally I've had a similar experience: hearing a song somewhere played on low-quality speakers and liking it, then later finding the high-quality version and not liking it as much.

I suppose it's nothing surprising, but I've had the opposite experience, hearing Michael Jackson's Thriller from SACD on highend speakers after listening to it from tape in my youth. *chefs kiss*
That's exactly how I feel about 4k TV or 48 or 60fps films. Unless it's sports or certain modern/comics action 720p with color depth seems about right. But as the Brian Eno quote says, it's what I'm used to or learned to like.

I remember I had one friend that when CDs came out didn't like them, but found that if he recorded them onto S-VHS tape sounded best of all, so he ended up using S-VHS like cassettes at home. In theory could have got a portable but that's taking it a step too far.

I listen to a lot of music and got 1/6.

I did a similar experiment to myself years ago with a MiniDisc player and found that 128kbps was indeed the sweet spot for myself. Especially when space mattered.

While I am sure that more expensive equipment or years of dedicated study can help me discern the difference, I don't feel like my lack of refinement hampers my enjoyment of music in any way. If anything, I have no interest in training myself how to notice peas under mattresses.

I am glad there are people who master their medium; but I can't be a master of all media and the intricacies of their particular language, history and references -merely to consume them.

Live and let live. I'd like less judgement for being like The Matrix character Cypher:

“I know this steak doesn't exist. I know that when I put it in my mouth, the Matrix is telling my brain that it is juicy and delicious. After nine years, you know what I realize? Ignorance is bliss.”

Edit: clarity of point.

4/6, never picked 128kbps.

Used $50 Audio Technica ATH-M20X on $90 Behringer UMC202HD.

Did audio production in the past (amateur level).

Failed Coldplay, and Neil Young, the latter I argue has such poor source quality that it's hard to tell a difference.

Tip: listen to the "air" of you want to spot the difference, that's the first stuff the compressors throw away. "Air" is the ambient sound of the room, the tail of the reverb, the stuff you hear when you don't hear anything if that makes sense.

I was able to distinguish the 128 kbps file every time (they sounded "muddy" to me), but the 320 / uncompressed wasn't distinguishable.

In particular, the coldplay song is one I've listened to alot, and I was able to instantly tell the difference in the instrumentation.

Listening on Apple Airpods Max, audio is getting piped through a virtual audio device via Loopback.

Listening on my bluetooth Plantronics headphones in a fairly noisy environment, I can't tell them apart at all.

That said, maybe the headphones compresses the wav as well...

All bluetooth is compressed with a variety of algorithms. Some are better than others, but none are lossless (not even aptX-HD). I believe Apple is about to release a firmware update that they claim will allow some of their cans and buds to support ALAC, which is lossless, IF you have Bluetooth 5 devices, and only use it short range. My guess is that it will dynamically degrade down to AAC-256 if the devices are too far apart. Bluetooth 4 devices cannot support lossless simply because they do not have sufficient bandwidth.
I found a cheat. At least on my system, the WAV version takes ever-so-slightly longer to begin after you click play.
When I was at Berklee [0] we had considerable ear frequency response training that would involve weekly hearing quizzes where they would boost/buck certain frequency bands of either pink noise or music and you had to pick out which band was made louder or softer. Additionally, we had a quiz where you had to listen to lossless vs mp3 at different bit rates and determine which was which. We also did neat things like trying to pick out what type of guitar and pickups someone was using in a recording simply by ear.

320 kbps mp3 vs lossless 16bit WAV (cd quality) is extremely difficult to hear the delta without training, but if you know what the source instruments are supposed to sound like, such as hats and you can focus on their frequency band, you can hear compression artifacts and comb filtering.

This course really changed how I take in music and sounds in general.

[0] https://online.berklee.edu/courses/critical-listening-1

So what are the characteristics of has that make them noticable? Would it high-freqency almost random noise?

I think of how mpeg video cannot accurately portray looking at a rippling lake.. the sinusoidal motion does not have much in common with blocky mpeg.

Audio has its own equivalent. It's not noise, it's more of a gargly quality. You can hear it very clearly at more extreme compression settings.

The overtone movements become disassociated and start splitting up into disconnected sine wave blocks. Transients also become softened.

With MP3s this is obvious at the high end, while lows/mids sound passable. The compression algorithm has more frequency bins at the high end, so the damage is more obvious there.

There's also a loss of low-level detail. Reverb tails lose definition, and the music loses front-to-back depth.

Which headphones/speakers would you recommend/do you use?
In my experience I will hear a shimmering effect that sounds like a tremolo where the volume of the hi-hats and other cymbals are fluctuating. It also causes the overall sound of cymbal crashes to be mushier and less distinct. In addition I've noticed an effect where certain sounds such as the attack of high-gain guitar is stretched and doesn't sound consistent throughout a song. It seems like these artifacts are most noticeable in higher frequency ranges or perhaps transients.
There's something about the really low tones that simply... changes at lower bit-rates. High-frequency tones are somehow clearer when uncompressed. It feels like the tones are right, but the waveforms distorted. Your rippling lake MPEG analogy is pretty much spot on.

That being said, age, tinnitus and amazing progress within the audio compression sciences have made it more difficult for me to separate uncompressed WAV and 320 kbps MP3, though the 320 kbps files in the article had noticable artifacts in most cases.

does it ruin your appreciation for great music in lower quality formats?
Not OP, but just a random ex-audio guy who did his fair share of listening experiments with different formats and bitrates.

FWIW, it had the complete opposite effect on me. I stopped caring about things like flac or other lossless formats for general music listening.

If the only way to maybe sometimes pick out a 320kbps mp3 from a flac one was to be on my best headphones, in my quietest room, focusing all my attention... the difference doesn't matter for practical listening. My ears may just be garbage, but it made me skeptical of people who make bold claims about what minutia they can discern -- although magical claims are more prevalent in the audiophile world ("these cables sounds great!") than the actual audio production world.

Not an audio professional but I'm the sound guy for a nonprofit.

Along similar lines, I can't tell the difference between a $250 microphone and a crazy expensive mic in anything but ideal conditions -- and even then, I need to hear them side by side.

+1; there are so many more important factors before the smaller things start making a very noticeable difference. A Neumann U 87 into a 1084 or VoxBox will sound marvelous with good talent giving a great performance, but that performance would still sound damn good with a $100 Shure SM57/58 into a Focusrite interface costing about the same. It’s never been easier or cheaper to be able to make music that’s good enough to get plays on Spotify.

Buying a Ferrari won’t make you Michael Schumacher, but he could probably lap your car round a track faster than you ever thought possible.

+1, I think for those with even a little musical background, the brain fills in the details to a much greater extent, especially if it’s something you’ve heard before on a good signal chain / live. You know what’s there, so you know what to listen for, and your brain kinda just interpolates the rest.

This is not my idea btw, I read it somewhere, just forgot where I read it. Googling a bit around “musician audio quality ‘fill in the gaps’” didn’t ring any bells. I’ve been reading up on acoustics and audio engineering over the past year trying to get my personal music project together, so it may have just been from a book as well.

>does it ruin your appreciation for great music in lower quality formats?

As someone that has high-end gear, I can absolutely tell the difference in most cases between 320kbps MP3 and lossless when switching between the two versions of the same song. It's hard to put a finger on, but it just "feels" different to my ears/perception. However, after listening to exclusively one or the other for a few minutes or not A/B switching the same song, I have a much harder time detecting the difference.

Quality of the master and quality of the equipment matter much more, IMHO.

Not at all, but I do have much greater appreciation for the time that sound engineers took to cram as much frequency information into the fixed size spectrum box using level variation, panning, parametric equalizing, and compression. All of those things we had to listen for and critically evaluate in that class.
I was hoping the course you recommend would be available for the general public, but at >$1000, this is a no go. I would happily pay for something like this, but not this much. Can anyone recommend an affordable equivalent?
Harman Audio created a free "How to Listen" application years ago for both Mac and Windows, which "consists of a number of training exercises where different kinds of timbral, spatial and dynamic distortions commonly found within the recording and audio chains are simulated and added to music." It isn't about MP3 compression specifically, IIRC, but it's a good critical listening course.

But: while it's still available, it's about ten years old, and I have no idea if it still runs on modern hardware.

http://harmanhowtolisten.blogspot.com

There's a $8 or so app called hearEQ that trains you on the pink noise or music part of this I think.
The only one I got dead wrong was Coldplay. That also happened to be the furthest from my usual listening habits, I don't know if that had any effect.

For the others I picked at random one of the two that sounded the most similar. In no instance could I tell 320Kbps and WAV apart. Could have been just luck that I didn't pick 128Kbps more than once.

Hardware is Bose QC II on low noise cancellation, connected by wire to a MacBook Pro and ears, one of which can hear crickets, the other not.

I used a pair of Powerbeats (Bluetooth earbuds) and picked either the 320 or the Uncompressed WAV (3/3) on all of them.
The Neil Young track sounds muffled even in the uncompressed to me.
Can't say I did well on the test. Actually made a decision on 2 of them and got the 128kbps on one and WAV on the Suzanne Vega (which must have been luck). The rest I just clicked something to read the snippets.

And I've got HD598s and was listening through a UMC1820 interface.

That said, I'll take lossless FLAC files for a download any day, simply because it's future-proof in a way compressed audio isn't. I'm quite happy to listen at 320kbps on Spotify most of the time, or transcode to 96kbps Opus any FLAC I have when I load it on my phone.