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Can We Really Tell Lossless From MP3?
EddieSpinola writes "Everyone knows that lossless codecs like FLAC produce better sounding music than lossy codecs like MP3. Well that's the theory anyway. The reality is that most of us can't tell the difference between MP3 and FLAC. In this quick and dirty test, a worrying preponderance of subjects rated the MP3 encodes higher than the FLAC files. Very interesting, if slightly disturbing reading!" Visiting with adblock and flashblock is highly recommended, lest you be blinded. The article is spread over 6 pages and there is no print version.
I've been exposed to people who write audio codecs for a living. They can tell because they've become sensitive to the artifacts present in MP3s. They also can pick up problems with CD's that haven't been dithered properly. They can easily pick out MP3 even at 320kbps. These are specialists. But even in this study there was one individual who had a high success rate.
At 192K and a good pair of headphones with good material I think most people could learn pretty quickly to pick up the difference - loss of stereo image at higher frequencies is pretty easy to pick up.
There are also studies available that point out the advantages of high bit rate recordings - these enable the use of sophisticated filters that eliminate some of the issues present with CD sound. If you are interested and have a mathematical bent, look up the work of Meridian's Peter Craven. Again the differences can be detected by specialists. I'm old enough so that my ears are not good enough to pick up these improvements.
I rip to FLAC and convert for my portables because of these factors.
If you want to try some testing yourself visit hydrogenaudio. They have apps set up to do abx comparisons so you can test yourself.
One problem is the simple A/B and asking which people like better. Well that is fine if you are doing something like testing two compression formats to see which has a sound people prefer. That is not fine if the question can people tell the difference between compressed and uncompressed music. For that you need an ABX test. X is a reference uncompressed sample, A and B are randomized such that one is uncompressed, one is not. People are then asked to identify the one that is the same as X. A test like that lets you tell if people can hear a difference, regardless of if they like it or not.
Also there is another angle to why people might choose to use uncompressed music and that is if there is any additional processing (like equalization) planned for later. Psychoacoustic compression schemes can have problems when processed later. Reason being that they do rely on things like masking, in that because X is happening, we can't hear Y. However when the balance of the sound is altered, well then that isn't necessarily the case anymore.
How important is that? Probably not very in a lot of cases. However how important is storage space? Last I checked 1TB was under $100. Storage is cheap. There's not really a need to milk every last bit out of a file. FLAC'd discs are in the realm of 300MB for a full CD. Big deal. I'm got space to spare, so why not go lossless?
What it really comes down to is what is "good enough" really depends on the situation. Depends on the music (some kinds cause more trouble for encoders), the listener, the environment, storage constraints and so on. I mean 64k is good enough to recognize the music. A 64k AAC or WMA is fine, FM radio quality maybe, and even a 64k MP3 is listenable. Is there distortion over what was on the CD? Sure, but maybe it is good enough in some situations (like say you need to be able to transmit stereo audio on a single DS-0 channel).
I really don't like these tests that try to give the one magic rate is that is good enough for all situations. Especially when they use bad testing methodology.
Personally, I'm a fan of lossless compression because then there's just not any additional errors. I've got the space so why not eliminate potential problems?