I think I can say a little bit about this.
The easiest way to tell the difference between lossy and lossless compression are (as mentioned before) the artifacts.
http://ff123.net/index.html
This is a site that will tell you all about it. The more obvious artifacts can be heard by most people though a logitech speakerset of about $5. Other artifacts can be heard when using a decent headphone. And other (even less obvious) artifacts can only be heard by an audiophile with a HE90 etc, etc.
It also depends on the music that you are listening to. Tracks with higher bitrates in FLAC (or whatever lossless files) will suffer greater losses than tracks that are allready at a lower bitrate.
Classical music and rock tends to have a higher bitrate than country or pop.
Note: I can not advice you to actually try and figure out what all these artifacts are. You will have to throw away half of you collection of 128kbps mp3s. Since now you can hear nasty warbling sounds. (don't even ask what a warbling sound is)
You should only train yourself in hearing the difference when you are planning on buying a new harddrive that can store all those FLACs.
As for me. I do not own a HE90 with proper amplification so I will not be able to tell the difference between some tracks. I do own that logitech speakerset which I mentioned before. (the one that costs $10) I can safely compress my mp3s using lame V2, 190 vbr. Most of the times I will not be able to tell the difference when using a proper headphone.
Only really expensive equipment will make 128kbps mp3s completely unbearable.
It's funny really. Spending money to buy good headphones and amplification. And then spending some more on a huge harddrive.
P.S. WOO. My first post after reading these forums for over 2 years. It became inevitable I guess.
