Risso’s dolphin acoustics

Grampus griseus

The Risso's dolphin acoustic repertoire includes clicks as well as sounding pulse.

 

spec grampusgriseus 01

The whistles, although present, are rare and at frequencies between 8 and 16 kHz, as other species of dolphins, Risso's dolphin emits low-frequency vocalizations with a  strong harmonic component and with maximum energy around 1 kHz.

Spectrogram of Risso's dolphin vocalizations, sound pulses and clicks