The gestural score contains information about when a constriction in the vocal tract should be produced and it also contains information about the amount of constriction. The gestural score also shows when the gestures of the articulators overlap in time. The articulatory information is presented in terms of tract variables, which are the parameters of the combined articulators involved in certain tasks (e.g. lowering or raising the velum). Also see: articulatory speech synthesis.