Bit Depth

Bit depth refers to the number of bits used to represent each individual audio sample in a digital recording. It determines the dynamic range of the audio, which is the difference between the quietest and loudest sounds that can be accurately captured.

The standard bit depth for audiobook distribution is 16-bit, which provides a theoretical dynamic range of 96 decibels. This is more than sufficient for spoken word content, where the dynamic range between the quietest whisper and the loudest exclamation is typically much less than 96 dB.

Professional audio production often uses 24-bit depth during recording and editing, providing 144 dB of theoretical dynamic range. This extra headroom is useful during production because it reduces the risk of clipping (distortion from signals exceeding the maximum level) and provides more precision for audio processing operations like normalization and compression.

For AI audiobook production, most TTS engines output 16-bit audio, which is perfectly adequate for the final product. The key consideration is ensuring that any post-processing steps (normalization, format conversion, chapter assembly) maintain at least 16-bit precision throughout the pipeline to avoid introducing quantization artifacts.