“Smear is a granulation effect. It offers the basic parameters of sample-based granular synthesis, only the “sample” is a (maximum) one second buffer of incoming audio.
Four grains are created from the input, the sizes of which are random values between the minimum and maximum grain size controls. Individual level and panning controls are provided for each grain.
Smear also has a feedback control which is the level of the granulated signal that is fed back into the buffer to be further granulated. Thus, as a mult-tap granular delay Smear produces interesting results on a variety of inputs.
Further, smear offers a selection of the popular window shapes (Gauss, Hann, Blackmann, etc.) plus some non-standard shapes that produce more glitchy or percussive sounds.”
Source : ccrma.stanford.edu