Refers to fibrous tissue that remains after healing of an injury. In laryngology, leaving trauma out of the picture, scarring is most often seen in the context of surgery, radiation, or prolonged use of an endotracheal tube. If a wound is created, such as after removing a superficial vocal cord cancer, the tissue that results after complete healing is not as flexible as normal tissue would be; the scarred area typically does not vibrate well, or at all. Sometimes progressive fibrosis occurs after radiotherapy. It is thought that the reduced blood supply and lowered tissue oxygen level caused by radiation damage to microvasculature leads to the gradual replacement of tissue with fibroblasts, because they can tolerate lower tissue oxygen levels.