Check out this blog post and the sound file where the author covers the Alvin Lucier avant-garde recording “I am sitting in a room”.
In the original recording, Alvin records his voice in a room onto tape. The recording is played back into the room and recorded again. This is repeated over and over and interestingly it doesn’t take long before resonances in the room and audio system start to jump out and overpower the voice.
In this version he runs the loop through additional mp3 encoding until the voice is lost completely. This is a pretty good demonstration of what is lost when an mp3 converted to wav, then converted to mp3 again. I’ve had to do that before.
I recommend downloading the large file and importing it into your DAW, RX or other editing program.
Here is an excerpt from the 50min clip. The original file was over 100MB so I did not want to rehost it. It’s a flac file so there is no quality loss. First is the original, then first mp3 encoding, then 10th, then another closer to the end.