Fig. 5. The song of Eugryllodes pipiens. (A) Oscillogram of a single normal pulse within a multiple-pulse sequence. (B) Oscillogram of the pulse shown in A after filtering to remove frequencies below 4.5 kHz; this waveform has been amplified fourfold 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-F_D waveform (the song pulse after filtering out the peak at the dominant frequency F_D of the song pulse) shown in B (open circles); the frequency scale for the broad-band waveform is on the left and that for the without-F_D waveform is on the right. A, B and C use the same time scale. D, E and F show 3 ms sections (shown in A, B and C by vertical dotted lines and labels) of the waveforms shown in A and B: D from the start of the pulse, E in the middle of the pulse and F from the end of the pulse. For each, the thick line shows the broad-band waveform and the thin line shows the without-F_D waveform, amplified fourfold relative to the broad-band waveform. The time scales in D–F show the regions of the pulse that have been amplified. The vertical dashed lines in D–F show that the relative phasing of the broad-band and without-F_D waveforms remains nearly constant throughout the pulse. In F, the decay of the pulse after 21.5 ms is close to exponential with a quality factor (Q) of 23.