As they contain an important subjective part, those texts reflect solely the subjective opinion of their respective authors, and Mp3tech.org may not fully endorse what is expressed in those texts.

Listening tests of MP3 using different bitrates
1998 Gabriel Bouvigne

An Examination Of The Correlation Between Perceived Sound Quality And Frequency Response Of Current MPEG Audio Encoders
1999 Peter Miller

WMA 9 versus MP3
2002 Gabriel Bouvigne

48kbps AAC public listening test
2006 Gabriel Bouvigne