Rhythmic Grunt sound is prominent throughout. The Grunt 
at -1.5 seconds is really four grunts in rapid succession 
with frequency components at 40 c/s intervals. In con- 
trast, the Grunter that sounds at 5, 9, 13, and 16 seconds 
makes a single grunt with frequency components at 25 c/s 
intervals. The Motorboating sound is illustrated at 2 sec- 
onds and 11 seconds as a series of harmonic-component 
lines. Component spacing corresponding to a pulse repe- 
tition rate of 13 per second is apparent. As mentioned 
above and illustrated in figure 9A, the onset of this sound 
is unobtrusive, and the pulse-train intensity gradually in- 
creases during its 5-second duration to a dramatic climax 
followed by 4 seconds of silence before a repetition of the 
pulse train. Pairing of Motorboating pulse trains, such as 
shown here, iS a common occurrence. 
Figures 9B and 9C show five 20 c/s Short Pulses 
from -7 seconds to +44 seconds. As shown in figure 9C, 
the first, third, and fourth seem to shift from 28 c/s down 
to 19 c/s and appear at intervals of 20 seconds, approxi- 
mately, a characteristic interval for 20 c/s Short Pulses 
in this part of the Pacific. On the other hand, the second 
and fifth Short Pulses seem to be two of a kind, shifting 
from about 35 c/s down to about 22 c/s, and are separated 
by a long 45-second interval. 
Figure 9C also shows a typical Type I 20 c/s Long 
Pulse beginning at time -68 seconds and lasting roughly 
20 seconds, and a typical Type II 20 c/s Long Pulse begin- 
ning at -20 seconds, shifting from 22 to 19.5 c/s at -6 
seconds, and terminating at -2 seconds. This latter sample 
also shows a strong second harmonic. The other 20 c/s 
Long Pulse activity is indistinct, probably because the 
sources involved are at greater distances. 
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