Fig. 19.3

Illustration of the sperm whale’s nose anatomy (a). Red arrows show the trajectory of sound produced in the “monkey’s lips.” The solid arrow indicates the trajectory of the first pulse in a click, while the dashed line shows the trajectory followed by subsequent pulses (modified from Norris and Harvey 1972; Huggenberger et al. 2016). Waveforms of the multipulse structure of a sperm whale click: (b) the waveform of a sequence of clicks and (c) a single click are shown. Individual pulses within a click are indicated as p1–p4, and the inter-pulse interval (IPI) is shown in the inset (c) (modified from Norris and Harvey 1972). The IPI is thus proportional to the size of the sperm whale’s nose