Glossary → Audio fundamentals
Audio fundamentals

Lossy compression

Lossy compression shrinks audio by permanently discarding information judged least audible — the approach of MP3, AAC and Opus — reaching a tenth of uncompressed size or less.

Modern codecs are perceptually transparent for speech at modest bitrates, and speech recognizers are robust to sane lossy encoding. The one rule is to avoid repeated lossy re-encodes, which stack artifacts.

Related terms

Lossless compressionLossless compression (FLAC, ALAC) shrinks audio while preserving it bit-for-bit — decoding restores the exact … BitrateBitrate is the amount of data used per second of audio, in kilobits per second (kbps) — the main quality dial … CodecA codec (coder-decoder) is the algorithm that encodes audio for storage or transmission and decodes it for pla…

Frequently asked

What is Lossy compression?

Lossy compression shrinks audio by permanently discarding information judged least audible — the approach of MP3, AAC and Opus — reaching a tenth of uncompressed size or less.

Why does Lossy compression matter?

Modern codecs are perceptually transparent for speech at modest bitrates, and speech recognizers are robust to sane lossy encoding. The one rule is to avoid repeated lossy re-encodes, which stack artifacts.

What terms are related to Lossy compression?

Closely related concepts: Lossless compression, Bitrate, Codec — each has its own entry in this glossary.