music, bit-rates, hearing

[darkoshi]

It's very hard for me to tell the difference between an MP3 file encoded at a constant bit rate of 64 kbps and the original WAV file. Using foobar 2000's ABX comparator* on John Williams' "Duel of the Fates", I found one small section of the track where I could discern a very faint difference between the 2 versions. With 2 other songs, I couldn't find any sections where I could tell a difference.

With a constant bit rate of 48 kbps, I can tell a slight difference compared to the original WAV.
With a constant bit rate of 24 or 32 kbps, the difference is pretty obvious.

Considering the above, and considering that LAME's V9 variable bit rate setting is nominally 65 kbps, it makes sense that I can't tell any difference between the V9 VBR files and the original WAV files.

And yet V9 is LAME's lowest quality VBR setting. V0 is the best quality, at a nominal 245 kbps.

It puzzles me that some people can discern a difference between the V0 and V2 settings. Their hearing must be phenomenal. Or mine must be really bad. I know that I'm rather tone-deaf, but I didn't think that my overall hearing was bad. Maybe it is because I'm getting old and am missing out on various high notes.


*along with my headphones, or my computer speakers

Comments

[hebinekohime]

I find 128-192K MP3s slightly tinny, but close to the original; at 64-96K, they start to sound tinnier. It's really noticeable if I'm listening to 96K web radio (or Youtube, which compresses to 96K IIRC) as opposed to something encoded at a higher bitrate. Some files at 256K sound a little compressed, and I can't tell at all at 320. But that's highly subjective. It might be the equipment you're using, or your ears might pick up a narrower range of frequencies, or a little of both.

(I'm wondering if it might be easier to notice a difference with dance music, where the frequencies can go unusually high/low... on a mixer, I've noticed the bass spiking on a particular WAV I own, while its 224K MP3 counterpart stays at a moderate level throughout, and generally sounds a bit less 'dynamic')