About My MP3s
MP3 is currently one of the most popular and widespread compression formats for audio files. Audio is compressed for use on the internet in order to make file sizes smaller and download times acceptable to consumers.
Our MP3 sound files are made from uncompressed 24-bit, 48kHz master recordings. We use the highest possible MP3 compression of 320kbps (kilobits per second) in order to minimize compression artifacts. Experts agree that recordings compressed at 320kbps are extremely high fidelity, convey the full frequency range, and sound virtually identical to the originals – yet they are only one-fourth the size of their uncompressed counterparts!
Go here for Wikipedia’s technical explanation of the MP3 format.