What does "bit depth" refer to in digital audio?

Bit depth is a critical aspect of digital audio that defines the amount of information stored in each audio sample. It refers specifically to the number of bits used to represent each individual sample. A higher bit depth allows for a greater dynamic range and higher audio quality because it provides more possible values to represent the amplitude of the audio waveform at any given moment. For instance, a bit depth of 16 bits allows for 65,536 different amplitude values, while a bit depth of 24 bits increases that to over 16 million values. This increased resolution helps in capturing subtle nuances in sound, leading to a more precise and faithful reproduction of audio.

Other concepts like duration, number of channels, and frequency range pertain to different aspects of audio but do not define bit depth. Duration relates to how long the audio lasts, the number of channels indicates how many audio tracks are being used (such as mono or stereo), and frequency range speaks to the pitch or tonal quality of the sound. Understanding bit depth is essential in digital audio processing, as it directly impacts the quality and fidelity of sound reproduction.