sample rate
The number of times per second an analog audio signal is measured during digital recording.
In Depth
The standard CD sample rate is 44,100 samples per second (44.1 kHz), which can capture frequencies up to 22.05 kHz (just above human hearing, per the Nyquist theorem). Higher sample rates (48, 96, 192 kHz) capture ultrasonic frequencies and may provide subtle benefits during processing. The sample rate, combined with bit depth, determines the resolution and quality of a digital audio recording. The debate over whether higher sample rates produce audibly better results remains one of audio's most contentious topics.
The 44.1 kHz CD sample rate was chosen not for any acoustic reason but because it was the highest rate that could be stored on existing Sony U-matic video tape machines in the early 1980s.