Echolocation: high-frequency component in the click of the Harbour Porpoise (<i>Phocoena ph. L.</i>)

Abstract

Besides the already known low-frequency components of the Phocoena echolocation pulse, a narrow-band pulse of 0.1-msec duration, with the main energy between 110 and 150 kHz and a source level of 40 dB re 1 μbar at 1 m has been found. The properties of this pulse can explain how wires below 1-mm diam can be detected by echolocation. The results are consistent with the hypothesis that the emission is restricted to a narrow beam.