A process for forming flexible noise attenuating cutting line for use in rotary vegetation trimmers formed of at least two monofilament polymer strands bonded together in a twisted disposition or a single strand twisted about its central axis in which the strand or strands are extruded in a molten disposition through a single die that is rotated during the extruding step either to twist the two strands together about a central longitudinal axis or a single strand about its own longitudinal axis such that upon cooling, stretching and heating, a flexible noise attenuating line is created in a continuous online process.