Diminishing returns of higher mp3 bit rates : A literature review

Abstract: Digital audio is the by far most common way to listen to music today. It is therefore important to store audio files as efficiently as possible. A common way of doing this is by using compression, often with mp3 files. As with all non-lossless compression, some data is lost. The purpose of this literature review is to examine at what point the compression is indiscernible. Four research papers were studied and their results compared and compiled to draw a more broad-based conclusion to the research question. The papers all used A/B tests to test at what bit rate subjects could not tell the difference between a compressed and an uncompressed file. The results indicate that most people with consumer-grade equipment are incapable of discerning between mp3 files encoded at 128 kbit/s mp3 and uncompressed or lossless audio. With trained ears and high-end equipment, the cutoff bit rate is instead in the 256 kbit/s range.