Fig. 8. Stress–strain relationship for vocal ligaments from a female (top) and male (bottom) elk vocal fold derived in a stepwise procedure. The symbols with a strike-through indicate the rupture point of the respective vocal fold. The lines represent the regression lines calculated for stress–strain data between 0 and 0.8 strain, in both cases only for the left vocal fold. Note that data points `slip off' from the regression model above strain 1.0 in the female and strain 0.8 in the male. This holds true for all ligaments investigated.