Granular synthesis is a technique whereby a sound is ``segmented'' into short (5 to 50 millisecond) ``grains'' that are subsequently pieced back together in various ways to create new sounds.
The first use of the term ``grains'' to describe these fundamental sonic elements is attributed to Iannis Xenakis.
Grains are typically short to avoid the perception of pitch. They are windowed to avoid signal discontinuities that produce audible clicks.
The audible effect of a stream of grains is dependent on a variety of factors, including grain duration, grain spacing, grain density, and window shape.
The source signal from which the grains are derived can be a recorded or synthesized sound. The spectral content of the source signal will have significant influence on the results of the granular synthesis.