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Comment by 1ris | Hacker News Reader

That's not true. MP3 simply never gets transparent and you can notice with 5 dollar in-ears. And people in general notice. This leads to absurdities such as bitrates of 320 kbps, even thou these do not sound significantly better than 128 kbps and are still not transparent.

On the other hand 128 kbps AAC is transparent for almost any input. AAC is supported abou everywhere where mp3 is. The quality alone should be convincing. The smaller size make the usage of mp3 IMHO insane.

OTOH "the scene" still does MPEG-2 releases I think.

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I have listened to a lot of MP3 at different bit rates and with modern encoders and variable bit rates I can't tell the difference between anything above 160 Kbps - most of the time it is hard to tell the difference between 128kbp and anything higher. Really at 320kps you are entering the realm of fantasy if you think you can hear any difference.

This is not true. It is trivial for almost anyone to distinguish 320kbps mp3 from uncompressed audio, with built-in DACs and $5 headphones, with as little as 5 minutes of training.

[citation needed]

How can it not be true as I am describing my experience. Are you really telling me that I actually can tell when I say I can't?

You're also describing everyone else's experience:

> Really at 320kps you are entering the realm of fantasy if you think you can hear any difference.

It depends on the encoder, the track, your equipment, and how good you are at picking out artifacts. Some people do surprisingly well in double-blind tests, though I doubt anyone can do it all the time on every sample.

There is no scientific evidence that anyone can do it at all above 192 kbps.

This is why ABX testing is so big in lossy audio circles. People can and do demonstrate their ability to distinguish between lossy and lossless encodings with certain samples in double-blind tests, at all sorts of bitrates. I've done it myself occasionally.

That people have been doing this for many years is one of the big reasons modern encoders are so good - they've needed tonnes of careful tuning to get to this point.

Like the parent comment, more bold statements about perceivable sound quality, with no evidence.

I absolutely heard a difference between 320 and everything below. You can tell me I didn't, but I did. There is a world of difference between 160Kbps and 256, and 128 is a lot worse. If you can't hear it, I understand, but the blame isn't the algorithm -- it is your equipment, your song selection, or your ears.

You are making some bold statements about the general transparency of different audio formats that contradict pretty much everything I've read about this topic so far. Hence, I'd like to learn more, do you have any links that you would recommend?

Well, try it yourself :). Make sure to make it blind-test with the help of somebody else. Ideally such things would be subject to scientific studies. But these are kind of expensive and nobody cares for mp3 anyway. I'm not aware of any recent.

Hydrogenaudio listening tests [1] are studies by volunteers, but they focus on non-transparent compression. Anyway, it also illustrate aswell how bad mp3 is.

[1] http://wiki.hydrogenaud.io/index.php?title=Hydrogenaudio_Lis...

You realize that that test doesn't test anywhere near 320kbps mp3, right?

Yes, that's what the last two sentences are about.

This page says at 128 Kbps all the encoders were the same (a 5 way tie). Their wiki says at 192 Kbps MP3 is transparent [1].

1. http://wiki.hydrogenaud.io/index.php?title=Transparency

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