Sample rate

The sample rate of a digital sound is the number of samples taken each second. Each sample records the height (amplitude) of the sound wave at that moment. Sample rate is measured in hertz (Hz), where 1 Hz means one sample per second.

A higher sample rate takes more samples every second. The stored points follow the original wave more closely, so the reconstructed sound is more accurate and playback quality is better. A sudden peak or dip in the wave is also more likely to be captured rather than missed between samples. However, more samples means more data, so the file is larger. For example, recording a doorbell chime at 4,000 Hz takes 4,000 samples each second, giving a more faithful recording than the same chime at 1,000 Hz — but the 4,000 Hz file is bigger.

A lower sample rate takes fewer samples each second. Some of the wave's detail is missed, so the playback is less faithful and the file takes up less storage.

Changing the sample rate changes how often samples are taken, not the number of bits used to store each sample. The bits per sample are set by the bit depth, which is a separate setting.