“…As presented in a recent review, 1 previous studies aiming to describe voice conditions following vocal demand, which used a variety of methods, populations studied, and measurements, yielded mixed and contradictory observations. 13,14 For instance, some studies showed a significant increase in F0 after prolonged voice use, whereas others reported a significant decrease. 1,2,5,6,17,19,25 A similar discrepancy between studies has been observed for other voice descriptors such as HNR, 1,2,17,25 jitter, 1,2,6,17,19 and shimmer.…”