If you are big on audio or if you just want to test your hearing then Audiocheck.net is a good resource. You can test to see if you can tell the difference between 8 bit and 16 bit audio, learn about sound terminology, perform blind audio tests, read earplug reviews and in general get a whole lot smarter about audio in general.
This site even allows you to download and burn a test CD so you can test all sorts of audio systems.
Just for fun I tried the 16 bit vs 8 bit audio test and at first I could not tell the difference until I tried the page explaining down-sampling, Dithering and Noise Shaping and this illustrated the difference nicely for me. I found that the examples showed me how 8 bit sampling introduced a hiss into the audio but back on the blind tests I could still not pick up the difference between the two samples. This led me to understand that most music sounds pretty much the same in most cases regardless of the sample rate being 8 bit or 16 bit. I will still however opt for higher sample rates where possible because if you can get better quality for free, why not?
I then went on to test my headphones and found the frequency response was between 20Hz and 13Khz. A few other tests covering dynamic range and bass shaker left me feeling pretty good about my headphones. I did however have my doubts about my own hearing and might recruit one of my kids to make sure that it is not my own ears that are failing me.
The site is simple, and a project of Audio Engineer Dr Ir Stephane Pigeon who is a bit of a fan of the Pigeon. Dr Stephane is currently looking for advertisers to support his site so this free site can continue to develop.
Dr Stephane’s page : http://www.stephanepigeon.com/