Introduction to Computer Music: Volume One

Sounds from the real world can be recorded and digitized using an analog-to-digital converter (ADC). As in the diagram below, the circuit takes a sample of the instantaneous amplitude (not frequency) of the analog waveform. Alternatively, digital synthesis software can also create samples by modeling and sampling mathematical functions or other forms of calculation. Frequencies will be recreated later by playing back the sequential sample amplitudes at a specified rate. A sample in either case is defined as a measurement of the instantaneous amplitude of a real or artificial signal. Frequencies will be recreated later by playing back the sequential sample amplitudes at a specified rate. It is important to remember that frequencies, phase, waveshape, etc. are NOT recorded in each discreet sample measurement, but will be reconstructed during the playback of the stored sequential amplitudes.

Samples are taken at a regular time intervals called the sampling rate. The sampling rate is responsible for the frequency response of the digitized sound.