The Listening Test from a few weeks back was interesting.

I had a few votes come in by email, and adding those to the ones made publicly in the comments, we get this result:

File 1:

• 63% said it was the 75% WMA
• 25% said it was the FLAC
• 12% don’t knows

63% of respondents were correct: File 1 was indeed the 75% WMA.

File 2:

• 63% said it was the 10% WMA
• 25% said it was the 75% WMA
• 12% don’t knows

63% of respondents were indeed correct. File 2 was the 10% WMA.

File 3:

• 88% said it was the FLAC
• 12% said it was the 10% WMA

Most people got this one right: File 3 was indeed the FLAC.

So it seems as if most people really can tell the difference between uncompressed and compressed music formats -but it’s a relatively narrow call when it comes to telling the difference between gentle compression (75% WMA) and drastic compression (10% WMA). Most people got it right even so, but the margin was quite a bit narrower.

I asked the question because (I am somewhat sad to find) I couldn’t tell the difference between the FLAC and the 75% WMA, in good listening conditions (Bose speakers, etc), despite the one file being just 15% the size of the other. It would seem my ears are not as good as I thought (it expect it comes with age!) Happily, I could spot the 10% WMA a mile off, the compression artifacts making me grit my teeth at one point.

I then tried the experiment on the train, listening via ear-buds and playing from a Samsung Galaxy SII phone: and all three files sounded exactly the same, perhaps unsurprisingly (everything sounds crap on a train!)

The point being that, as I approach 50, it’s perhaps unnecessary for me to upgrade my RAID array from a mere 8TB to 12TB (which will cost a bomb, with 3TB hard disks still costing around the AU$300 mark). I could compress all my music files instead, saving as much file capacity as I was planning on adding, and I’d never tell the difference. (Except that, of course, I would know, intellectually, that frequencies were missing, and that would annoy me no end. So I’m sticking to FLACs for now, even though they are unnecessary for my particular pair of ears!

These three files are of the same 57-second piece of music. One was ripped to FLAC, one was ripped to a 75%-quality WMA and one was ripped to a 10%-quality WMA:

• File 1
• File 2
• File 3

When you look at the original file sizes involved, the FLAC is 3MB, the 75% WMA is 510KB and the 10% WMA is just 200KB.

However, I’ve now converted all three files back to [uncompressed] WAV, so that -give or take a dozen bytes or so- all file sizes are pretty much identical (9MB or thereabouts). You won’t be able to tell which is which just by comparing file size, in other words, but each has been encoded at wildly different quality levels.

So the question is, can you tell which file is which, just by listening (checking the wave form in something like Audacity is not allowed!)?