hem: the utterance of a sound similar to clearing the throat; intended to get attention, express hesitancy, fill a pause, hide embarrassment, warn a friend, etc.
utterance: the use of uttered sounds for auditory communication
xerox: a duplicator (trade mark Xerox) that copies graphic matter by the action of light on an electrically charged photoconductive insulating surface in which the latent image is developed with a resinous powder