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Bob Kraushaar, a sound engineer, explains the differences between analogue and digital sound recording.

A microphone captures the changes in air pressure created by a sound wave and translates it into a small electrical voltage. This produces a continuous representation of the sound or an analogue signal. By contrast, a digital signal is composed of thousands of tiny snapshots of sound, called samples.

The quality of a digital recording depends on how many of these snapshots are taken per second, known as the sample rate, and how sharp the focus of each snapshot is, known as the bit depth.

Bob plays around with the sample rate and bit rate of a piece of music to demonstrate sound degradation.
This clip is from:
First broadcast:
5 March 2009

Classroom Ideas

Could be used to teach the difference between analogue and digital signals, and their advantages and disadvantages. Students who are designing and making products that play music could use the information as research for their controlled assessment task.