Each added quantization bit yields 6dB SNR improvement

Evidence

Quantization with finite precision generates an error called quantization noise. The signalto-noise ratio (SNR, see Section 4.2.6) describes the level of the signal compared to the level of noise, and for quantization noise it improves by 6 dB for each added bit, so that 16 bits, often used in audio, yield a maximum SNR of about 96 dB. Because the dynamic range of the auditory system is about 130 dB, even more than 22 bits may be needed. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 408

Categorization

• DEFINE: Quantization noise is defined and quantified against bit depth.
• XREF: Pairs with the book’s earlier discussion of the auditory system’s ~130 dB dynamic range as the benchmark for digital fidelity requirements. — connects to: Higher bit depth reduces quantization noise by resolving more amplitude values — Almo Farina, Soundscape Ecology: Principles,…, 1959