Glossary → Audio fundamentals
Audio fundamentals
Sample rate
Sample rate is how many times per second an audio signal is measured when converting sound to digital data, in hertz — 44,100 Hz (44.1 kHz) is the CD standard; 48 kHz dominates video.
By the Nyquist theorem, a sample rate captures frequencies up to half its value — 44.1 kHz covers the ~20 kHz limit of human hearing. Speech is intelligible far lower (phone audio is 8 kHz), which is why speech models commonly process 16 kHz audio.
Higher rates than 48 kHz matter for production headroom (pitch shifting, slowdowns), not for playback fidelity.
Related terms
Bit depthBit depth is how many bits describe each audio sample — 16-bit (CD) gives about 96 dB of dynamic range; 24-bit…
Nyquist theoremThe Nyquist–Shannon theorem states that a digital system can perfectly capture frequencies up to half its samp…
ResamplingResampling converts audio from one sample rate to another — 48 kHz video audio to 16 kHz for a speech model, o…