Fig. 7. Anomalous pulse from the song of the same Gryllus campestris as in Fig. 3. (A) Oscillogram of a single pulse of a chirp of the song. (B) An oscillogram of the pulse shown in A after filtering to remove frequencies below 7.5 kHz; this waveform has been amplified 16-fold relative to that shown in A. (C) Plot of the cycle-by-cycle frequencies of the broad-band waveform shown in A (filled circles) and the without-FD (the song pulse after filtering out the peak at the dominant frequency FD of the song pulse) waveform shown in B (open circles). Before 3 ms, both waveforms were very irregular; after 10 ms, the without-FD amplitude became very small. The cycle-by-cycle frequency data in these regions have been deleted. The frequency scale for the broad-band waveform is on the left and that for the without-FD waveform is on the right. A, B and C use the same time scale. The asterisks show the time at which the broad-band waveform started to decay exponentially and the cycle-by-cycle frequency of the broad-band waveform rose by 0.2 kHz, thereafter remaining nearly constant. (D,E) 3 ms sections of the waveforms shown in A and B; D is from the irregular region at the start of the pulse and E is from the region around the irregularities in the waveforms. For both, the thick line shows the broad-band waveform and the thin line shows the without-FD waveform, amplified 16-fold relative to the broad-band waveform. The time scales in D and E show the regions of the pulse shown in A that have been amplified. The vertical dashed lines in D and E show the relative phasing of the broad-band and without-FD waveforms. In D, the box shows the region in which the cycle-by-cycle frequency of the broad-band waveform rose rapidly. In E, the horizontal dashed line shows the region of the pulse in which the without-FD waveform increased and then became small in amplitude; this was associated with the start of the exponential decay of the broad-band waveform. The quality factor (Q) of the exponential decay is shown.
