I'll believe it's just my ears when people who insist they can hear a difference do a controlled, line level matched blind A/B comparison and verify that it isn't just their mind!
Whenever I consider new technology or new equipment, I take the time to test it- not with scopes, but in real world listening situations. I have a tremendous amount of money invested into music with nearly 10,000 CD and at least as many records. Before I was going to start digitizing and building a library on a media server, I wanted to make sure I knew exactly what the optimal settings were, not just for sound quality, but for drive space.
The thing that most people don't understand is that compression artifacting isn't like analogue distortion. It doesn't fade in subtly. A bitrate either artifacts, or it has sufficient bandwidth to accurately reproduce the music. Artifacting has a specific sound. It's a "digital gurgle" that is unmistakable. It isn't a "veil over the sound" or subtle muffling. Anyone who describes compression artifacting that way is making it up.
I tested a range of codecs and settings, and discovered that there was a point where artifacting fell away. It was a different point for different types of music. Electronic music was very forgiving, one particular orchestral string texture was difficult to encode without artifacting. I took the setting where the artifacting disappeared on the most difficult sample and upped it one notch, just to be safe. That came out to AAC 256 VBR.
Since then, I have ripped a year's worth of music of all types- from Edison cylinders to the most modern digital recordings- at these settings and fed the files into my media server. I have yet to find a single file that doesn't sound exactly like the original CD. No one wants to encode music and then find out they need to start over. I made sure that wouldn't happen.
I've done the legwork and taken the time to make sure I'm right. I know by the expressions of amazement of my friends when they listen to my media server that my ears are just fine.