Sampling Rate

The sampling rate refers to the process of converting a continuous signal into discrete units of time. Whether recording sounds, capturing images or processing an electromagnetic wave, many sources of information are continuous or analogue in nature. Before digital devices can make sense of the such information, the data must be converted. This involves taking snapshots of the signal so that it can be manipulated and reassembled into a readable format. The speed at which these snapshots are taken - usually measured in seconds - is known as the sampling rate.

The conversion is performed by an analogue to digital converter. The converter turns physical information such as sound, light and temperature into a pattern of numbers that the computer can understand.

Sample rates are measured in Hertz (Hz). Higher sampling rates produce better quality media. In video, the sampling rate determines how often the light intensity of each video line is sampled. The sampling rate also determines the frame rate. A frame rate of 24 frames per second is required to prevent flickering.

In audio, most content has a sampling rate of 44.1 kilohertz, which is equivalent to the maximum bandwidth audible to most humans. However, a lower rate may be selected to reduce file size, conserve CPU usage or where the sound quality is unimportant.