Audio bitrate is the amount of audio data used per second of playback, typically measured in kilobits per second (kbps). Higher bitrate means more data to represent the audio — better quality, larger file size. Lower bitrate means more aggressive compression — smaller files but quality loss. For MP3, the standard bitrate range is 32-320 kbps; for AAC, similar range with better quality per bit.
Practical bitrate guidelines: 64 kbps — acceptable for voice/speech only; 96 kbps — decent quality for music on headphones, noticeable compression; 128 kbps — MP3 standard quality, good for casual listening; 192 kbps — high quality, most listeners cannot distinguish from original; 256 kbps — very high quality, near-transparent for most people; 320 kbps — maximum MP3 bitrate, transparent for virtually all listeners.
CBR (Constant Bitrate) uses the same bitrate throughout — predictable file size, consistent quality. VBR (Variable Bitrate) allocates more bits to complex sections and fewer to simple passages — better quality per file size, variable final size. VBR at quality V0 (highest quality VBR) is recommended over CBR 320 for archiving: similar quality, significantly smaller file size. FileCurve's audio compressor allows selecting output bitrate.