In 1996 a two-week expedition to the Walrus Islands in the Bering Sea was undertaken to record the sounds of Pacific walruses, both for use in musical compositions and to add to the baseline data on acoustic disturbance and walrus behavior collected by the Alaska Department of Fish and Game.
There was an opportunity during the expedition to use a hydrophone to record the animals’ underwater communications, which include a gonging sound, whistling, grunting, roaring, and clacking of teeth.
This according to “Toothwalkers” by Douglas Quin (Terra nova: Nature and culture II/3 [summer 1997] pp. 88–96). Toothwalker refers to Linnaeus’s designation of the walrus as Odobenus rosmarus (tooth-walking sea horse).
Below, the celebrated E.T. demonstrates his repertoire and expertise.