A pre-finished piston part is disclosed that may be used to form a piston assembly. Each segment has a time interval within the utterance, and scores characterizing the degree of match of the utterance in that time interval with a set of subword units. Then assign a value to the spatial extent, which varies as a function of distance from the adjacent structure to the given structure. A wire retainer is engaged upon the plurality of wires to maintain the wires in a fixed position.