Uncompressed PCM vs Lossless FLAC vs Psychoacoustic MP3/AAC

Audio compression falls into two categories: lossless compression (which preserves 100% of the mathematical data) and lossy perceptual compression (which discards acoustic information deemed inaudible to human ears).

Uncompressed Linear PCM (WAV & AIFF)

Linear Pulse Code Modulation represents uncompressed sample measurements stored in standard RIFF (WAV) or IFF (AIFF) containers. It requires zero decompression CPU overhead but consumes maximum disk storage (~10 MB per minute of stereo 44.1/16 audio).

Lossless FLAC (Free Lossless Audio Codec)

FLAC utilizes linear predictive coding (LPC) and Rice entropy encoding. Much like a ZIP file tailored specifically for audio, FLAC reduces file sizes by 40% to 60% while guaranteeing bit-for-bit mathematical identity upon decompression.

Lossy Psychoacoustic Codecs (MP3 & AAC)

MP3 and Advanced Audio Coding (AAC) employ the Modified Discrete Cosine Transform (MDCT) combined with psychoacoustic masking models. Frequencies hidden behind louder adjacent sounds (simultaneous masking) or sounds occurring immediately after loud bursts (temporal masking) are discarded, achieving 70% to 90% file size reductions.