Table 1.

Acoustic parameters (mean ± s.d.) of bio-duck (N = 6/n = 41 pulses) and downsweep (N = 26) sounds recorded on two acoustic recording tags. n(P), number of individual pulses; PF, peak frequency; CF, centre frequency; Q25, first quartile frequency (25%); Q75, third quartile frequency (75%); DUR90(P), 90% energy duration of individual pulses/downsweeps; RMS RL, RMS received level.

n(P)PF (Hz)CF (Hz)Q25 (Hz)Q75 (Hz)DUR90 (P) (s)RMS RL (dB re 1 μPa)
bio-duck7 ± 3154 ± 13155 ± 13146 ± 12165 ± 160.1 ± 0.0140.2 ± 3.6
downsweep83 ± 1784 ± 1775 ± 1594 ± 150.2 ± 0.1147.3 ± 5.3