Dynamic range is the ratio between the maximum and minimum signal levels a system can handle, expressed in decibels (dB). A wide dynamic range means the system can capture both very quiet sounds and very loud sounds without distorting at the top or disappearing into noise at the bottom.
Human hearing has a dynamic range of approximately 120 dB — from the threshold of hearing (0 dB SPL) to the threshold of pain (around 120 dB SPL). A 16-bit digital audio system captures about 96 dB of dynamic range; 24-bit captures about 144 dB — well beyond the limits of any microphone or human perception.
In practice, microphone self-noise sets the bottom of a recording's dynamic range, and the analog-to-digital converter's maximum input level sets the top. The dynamic range of the recording chain is: maximum SPL before clipping minus the self-noise floor.
Compression reduces dynamic range intentionally — bringing loud and quiet moments closer together in level. This is used in music production, broadcasting, and podcasting to create consistent, controlled audio. Heavy compression can make a recording sound punchy and present, or lifeless and fatiguing depending on settings.