If you feel like you have a few minutes to spare (something I don't, but I spent them anyway), you should give this a try:
It's an interesting experiment on:
- The quality of your speakers/headphones
- Your ability to see the difference between audio compression parameters for the same compression algorithm.
A more complete study would include:
- More types of music (I remember hearing quite a difference between music that has too much silence and music with too much equal noise)
- More compression algorithms (this makes it even harder to judge, but it's interesting to put them side-by-side on different types of music)
As most people, it's easy to tell what is the 64K compression. The rest becomes more subjective. I found that I was barely able to tell any difference between the other two using my speakers, but with my headphones (Sennheiser), I was able to sense something. Not very huge difference, but there was something there.
The funny thing would be to find out that there was no difference and people were making it up because he said there would be three different compression rates.