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Topic: Artifact training (Read 8474 times) previous topic - next topic
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Artifact training

Hey everybody,

OK, I have been going through ff123's artifact training page to help me learn to hear the artifacts.  Now, I had gone through this process before using my extremely crappy PC speakers and was able to pick out most of the artifacts, some easier than others.  However there were a few that were either quite difficult for me, or I flat out couldn't hear the artifacts.  So I switched to using headphones (certainly not high quality ones, mind you) hoping that the artifacts would become more aparent.  Indeed, 8 out of the 9 samples were now utterly easy to pick out the artifacts.  However, Sarah McLachlan's Wait was one that I couldn't abx before, using the crappy speakers, and for the life of me, I still can't abx it with the headphones!  I believe I know what I am supposed to be listening for from the description on ff123's page, but man....I hear something like what he describes in the cymbols, but in both samples, so it must not be the artifact.  I was using the psudo reference file against the Xing 128 kbit/s, and I thought maybe there is a very slim chance that I am hearing the same artifact in the -insane encoded file, so I switched to using the original .flac file for the reference.  As expected, still no difference.

So, I guess my question is, how would you describe what you hear as the artifact?  Maybe what I think I am supposed to be listening for from ff123's description just isn't clicking with me.  Anyone else have their own description that might help me to understand what to listen for?

FYI, I'm using a crappy radioshack headset as my headphones (could possibly be the problem, but man...if I can hear the other artifacts so distinctly.....) and a SoundBlaster 512 PCI for a sound card.

Thanks in advance!

Artifact training

Reply #1 –
Quote from: yodalige on
Hey everybody,

OK, I have been going through ff123's artifact training page to help me learn to hear the artifacts.  Now, I had gone through this process before using my extremely crappy PC speakers and was able to pick out most of the artifacts, some easier than others.  However there were a few that were either quite difficult for me, or I flat out couldn't hear the artifacts.  So I switched to using headphones (certainly not high quality ones, mind you) hoping that the artifacts would become more aparent.  Indeed, 8 out of the 9 samples were now utterly easy to pick out the artifacts.  However, Sarah McLachlan's Wait was one that I couldn't abx before, using the crappy speakers, and for the life of me, I still can't abx it with the headphones!  I believe I know what I am supposed to be listening for from the description on ff123's page, but man....I hear something like what he describes in the cymbols, but in both samples, so it must not be the artifact.  I was using the psudo reference file against the Xing 128 kbit/s, and I thought maybe there is a very slim chance that I am hearing the same artifact in the -insane encoded file, so I switched to using the original .flac file for the reference.  As expected, still no difference.

So, I guess my question is, how would you describe what you hear as the artifact?  Maybe what I think I am supposed to be listening for from ff123's description just isn't clicking with me.  Anyone else have their own description that might help me to understand what to listen for?

FYI, I'm using a crappy radioshack headset as my headphones (could possibly be the problem, but man...if I can hear the other artifacts so distinctly.....) and a SoundBlaster 512 PCI for a sound card.

Thanks in advance!


What may be obvious to me may not be obvious to you (obviously).  My hearing currently rolls off above 16 kHz, so if your hearing response is different, the artifacting may be masked.  It's also possible your headphones are masking the artifacting.

In any case, if you're really interested in training your ears, just encode a lot of different music which you're familiar with and start listening closely.

ff123

Artifact training

Reply #2 –
Quote
What may be obvious to me may not be obvious to you


Quite true...However, considering that every one of the other samples are completely obvious in the headphones, I would like to make a serious attempt to learn to pick out this artifact, especially since it sounds like from your description that this is a classic problem, at least with this encoder...

I have attempted to abx my own music, however, I thought that before I got too heavily into it, I wanted to make an attempt to train my ears to hear some of the different types of artifacts that I may encounter.  So, I was thinking that maybe if I got a little more detailed information about the artifact, I may be able to pick it out...

Quote
My hearing currently rolls off above 16 kHz, so if your hearing response is different, the artifacting may be masked


It sounds like from this that this artifact appears mostly in the extreme upper frequencies (also from the fact that it is in the cymbols).  You mention on your page that it sounds "as if I were listening to a large piece of sheet metal being moved back and forth"...Does this effect kind of quickly oscillate in the continuous background of cymbols, or is it more like the effect happens once per cymbol hit (the sheet metal waves back and forth once per cymbol hit)?  Also, is there any particular time during the sample that you hear it most pronounced?

It may end up that my ears simply don't respond well at the frequencies that this artifact affects.  Indeed, if this artifact shows up in a much different frequency range than each of the other 8 artifacts on the page, then that could be quite possible.  I actually have not done any tests of my ear's frequency response, so I don't know where my hearing rolls off.  And of course, admittedly, I don't have access to a good pair of head phones, however, I do have a reasonably good home theater set of speakers, and I haven't tried listening to the sample through it yet....I would have to burn a cd with the sample on it, and I probably will try that.

Any more detailed info you can give me would be most helpfull...and of course, anyone who has listened to this sample, or knows of another sample with the same artifact is welcome to chime in. 

Thanks again!

Artifact training

Reply #3 –
Argh. The cymbals are grating. It basically oscillates the entire time.
I have an easier time hearing this on my speakers than my headphones ('cause my headphones suck).
It's easiest to hear in the first two or three seconds in my opinion.

By the way ff123, I hate you. Your artifact training ruined me and now I hear artifacts everywhere.

Artifact training

Reply #4 –
Ask pepoluan for his artifact-unhearing-training or however he calls it^^

Artifact training

Reply #5 –
Nah, it just makes me appreciate LAME and encoding quality in general that much more.

Artifact training

Reply #6 –
Quote from: Firon on
Argh. The cymbals are grating. It basically oscillates the entire time.
I have an easier time hearing this on my speakers than my headphones ('cause my headphones suck).
It's easiest to hear in the first two or three seconds in my opinion.
I failed to do this one with my headphones (Beyerdynamic DT231s, which are good but not excellent) and suceeded fairly easily with my HiFi speakers (home build, home design, excellent measurements). I also succeeded with my movie speakers (Logitech Z-560), which I found fairly interesting as their quality isn't too good.

I have no idea why this sample seems much harder to me on headphones than speakers.

Artifact training

Reply #7 –
Quote
By the way ff123, I hate you. Your artifact training ruined me and now I hear artifacts everywhere.
lol, now you need to "exorcise" the ears.

i thank you Firon...
i was starting to download and now i'm running miles!

Artifact training

Reply #8 –
Quote from: Firon on
By the way ff123, I hate you. Your artifact training ruined me and now I hear artifacts everywhere.


Heheh, sucks sometimes doesn't it?  A while back my coworkers were listening to what must have been the worst encoded mp3 ever -- it was like glass piercing my ears -- and this was through the computer speakers in a noisy lab where you have to raise your voice to be heard.  When I told them I couldn't bear to listen they kind of looked at me with a blank face.

ff123

Artifact training

Reply #9 –
OK...So I burned a cd with the artifacts from ff123's page and played them on my HT speakers.  I found out a few interesting things.  One is that on the "daughter" sample, I find the artifact much easier to hear on the headphones than I do on my speakers (on headphones I hear the "knocking" artifact as more like someone is raking their finger across a carpet quickly, while on my speakers it does sound like a knocking on wood, and much harder to pick out).  I still havn't been able to hear the described artifact in "Wait"...I hear all sorts of oscillations (I hear these most clearly right after the second piano chord) in the cymbols (higher frequency oscillations on the order of 50/cymbol hit, some lower frequency ~10/cymbol hit, and at least one that I hear once per cymbol hit...), but they all also appear in the reference file.

However, while listening carefully I found that I do pick out pre-echo in the cymbol hits.  I abx'ed it (15/16...got a little lazy on the 15th).  The taps sound clean in the reference, while they sound a little smeared in the xing file (sort of like they were hitting the cymbols with a wire brush instead of a stick).

So, I don't know...maybe I must admit failure at this particular artifact (some might say this is a blessing though... ), but I'm not going to give up yet.  I do intend to continue trying to hear this artifact, so again, if anyone has any other discriptions that helps them pick it out, please let me know.

Artifact training

Reply #10 –
Quote from: ff123 on
Heheh, sucks sometimes doesn't it?  A while back my coworkers were listening to what must have been the worst encoded mp3 ever -- it was like glass piercing my ears -- and this was through the computer speakers in a noisy lab where you have to raise your voice to be heard.  When I told them I couldn't bear to listen they kind of looked at me with a blank face.

ff123


Aye, my parents were listening to some 64kbps WMA (ugh) tracks on the home theater, and I just couldn't bear to listen either. They insist it sounds fine though... Said I was too picky
 

Artifact training

Reply #11 –
Quote from: Hollunder on
Ask pepoluan for his artifact-unhearing-training or however he calls it^^
  It was "unlearning" ... and by waiting this long I think it is too late 

Okay, it may sounds like magic (read: quack-science ) but basically the premise is that our brain is reprogrammable through self-suggestion and self-hypnosis.

Here, let me give you a simple, step-by-step summary of what you should do:
  • Put your brain into alpha state -- you can use ambient tracks, or special tracks with alpha brainwave synthesized into it.
  • Find a 'good enough' track -- it might contain artifacts, but not that much that it's grating.
  • Play the artifact-y track, everytime you hear an artifact you say (audibly), "It's okay. It's good." A nod of the head helps.
  • Keep playing the same track 4-5 times, if possible after the 2nd play, play it loud but in the background (do it while knitting or doing macrame or whatever). Nod your head to the beat while you're doing this, or tap your feet, or drum your finger.
  • Sleep. Or take a nap. At least 30 minutes to allow REM-mode (i.e. dreaming state).
  • Repeat if necessary.

It is imperative that unlearning be performed before you rest from a tiring ABX session; if you have slept after you learnt the artifacts... the REM-mode of your brain may have (nearly) indelibly burn the artifacts into your long term memory. In which case unlearning becomes a honking royal PITA.