Table 1.

Click parameters from wild and captive harbour porpoises

ParametersWild porpoisesCaptive porpoises*
ASLpp (dB re 1 μPa pp @ 1 m)178-205157-172
ASL−10dB (dB re 1 μPa RMS @ 1 m)166-194
ASL95%E (dB re 1 μPa RMS @ 1 m)161-191
E−10dB (dB re 1 μPa2s @ 1 m)123-150
E95 (dB re 1 μPa2s @ 1 m)123-151
τ−10dB (μs)44-113(77-125)
τE (μs)57-175
fc (kHz)130-142
fp (kHz)129-145128-135
BW−3dB (kHz)6-26
BW−10dB (kHz)14-46
BWRMS (kHz)5-12
Q RMS(BW) 12-30
ICI (ms)30**-20020-110
  • ASL, apparent source level; pp, peak-to-peak; RMS, root mean square; E, energy flux density; τ, click duration; fc, centroid frequency; fp, peak frequency; BW, bandwidth; Q, fc/BWRMS; ICI, inter-click interval. It is unknown how the duration was measured in the studies with captive porpoises.

  • * Data from Au et al. (Au et al., 1999), Kastelein et al. (Kastelein et al., 1999) and Teilmann et al. (Kastelein et al., 1999).

  • ** A single sequence of very rapid ICIs (6 ms) was recorded, but not included in the data.