SampleRate

Sample rate, also written as sampling rate, is the number of samples of an analog signal taken per unit of time to represent the signal in a digital format. It is expressed in hertz (Hz), indicating samples per second, and determines the highest frequency that can be accurately captured according to the Nyquist–Shannon sampling theorem, which states that the sample rate must be at least twice the maximum frequency of the input signal.

In audio engineering, common sample rates include 44.1 kHz for CD audio, 48 kHz for digital video and many professional applications, and higher rates such as 96 kHz or 192 kHz used in high‑resolution recording. Higher sample rates can reduce quantization noise and improve the representation of transients, but they also increase data size and processing requirements. In telecommunications, sample rates are matched to bandwidth constraints, with typical values like 8 kHz for narrowband voice and 16 kHz for wideband speech.

Sample rate is a key parameter in digital signal processing (DSP), influencing filter design, aliasing prevention, and reconstruction of the continuous‑time signal through interpolation. When converting between different sample rates, resampling algorithms employ interpolation or decimation to avoid artifacts. The choice of sample rate balances desired fidelity, system resources, and the frequency content of the source material, making it a fundamental consideration across audio, video, medical imaging, and scientific measurement domains.