A method of designing a tread unit that may be repeated in succession about the circumference of a tire to produce an acoustically acceptable tread pattern. The impact of an initial design of a tread unit on a road surface is simulated so that a determination of the number of pulses contained in the impact may be made. An analysis is then performed, based on the number of pulses, as to whether the tread unit design satisfies a predetermined acoustic criteria. If the tread unit design satisfies the acoustic criteria, it may be incorporated into the tire tread pattern. Otherwise, the method may be repeated with a modified tread unit design until the predetermined acoustic criteria is satisfied.