Each additional bit of word length adds approximately 6 dB of dynamic range

Word length (bit depth) determines dynamic range in digital audio. Each bit contributes roughly 6 dB, so 16-bit audio offers ~96 dB of dynamic range, 20-bit ~120 dB, and 24-bit a theoretical ~144 dB. Recording and mastering at 24-bit provides far greater headroom and preserves more detail in quiet passages. The final CD Red Book format requires 16-bit, so dithering must be applied when truncating from 24-bit.

Examples

A 16-bit mix has ~96 dB dynamic range. Processing at 24-bit inside a DAW preserves accuracy. Applying dither before the final 16-bit export prevents truncation distortion.

Assessment

An engineer mixes at 24-bit and needs to export a 16-bit CD master. What must be applied before truncating the word length, and why?