sentences:  In Souter (2001), tempo was doubled from the first to the second reading, from 60 to 120 MM; thus, t = 2, and the number–duration curve is described by nd = 0.5 (Figure 2).In other words, factoring the proportional change in the number and mean duration of pauses between these readings will always equal ½.Each participant’s two readings thus corresponded to a point on this curve.