Sounds of the Deep

November 30, 2016 (updated 12/01/2016)

Passive acoustic monitoring provides details about the acoustic environments of cetaceans. Our program uses a variety of instruments to study cetaceans in the Pacific Islands Region. Below are examples of recordings of species found recorded using one of the following methods; towed hydrophone arrays, bottom mounted long-term acoustic recording devices and instruments attached to long-line fisheries gear.

CLICK ON EACH MARINE MAMMAL TO HEAR THEIR SOUNDShorn
bottlenose dolphin
Bottlenose Dolphin
rough-toothed dolphin
Rough-Toothed Dolphin
humpback whale
Humpback Whale
killer whale
Killer Whale
false killer whale
False Killer Whale
sperm whale
Sperm Whale
dwarf sperm whale
Dwarf Sperm Whale
pilot whale
Pilot Whale
blue whale
Blue Whale
mystery cetacean
Mystery Cetacean

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Blue Whale
Blue whales produce several different call types. Bouts of down-sweeping calls from ~80-45 Hz lasting 1-2 second duration are known as D calls and are generally associated with social and feeding behaviors. The ones presented here were recorded in November 2013 off the Kona coast of Hawaiʻi . Blue whale populations also have regionally distinct songs. These regional vocalizations are stereotypical and are made up of a series of distinctive calls (not shown).
Bottlenose Dolphin
Bottlenose dolphins make a wide variety of sounds including whistles, echolocation clicks, and other pulsed sounds. They often produce whistles with multiple upward and downward sweeps in a row. These sounds were recorded on a towed hydrophone array behind the research vessel as the dolphins were bow-riding.
Dwarf Sperm Whale
Dwarf sperm whales produce clicks at a very high frequency (~126 kHz), which is well above human hearing (max ~20 kHz), therefore no recording is included here. This image shows 5 seconds of a recording from a dwarf sperm whale. The animals use these echolocation clicks to navigate, find prey and communicate while at the surface and during their deep hunting dives when they go down to ~500 m. Although this species lives throughout the world in tropical and subtropical waters, there are only 3 known recordings of this species because they are difficult to locate and are shy of boats.
Dwarf sperm whale spectrogram.
Dwarf sperm whale spectrogram.
False Killer Whale
A pod of the main Hawaiian Island insular false killer whales produces a variety of low frequency whistles. They range from a single, flat tone to having multiple upward and downward sweeps.
Humpback Whale
Humpback whales produce complex songs and learn a new song each year, and that song gradually changes over the winter season. The audio clip has calls as low as 100 Hz and higher than 1,000 Hz. These calls were recorded in January of 2014 off the Kona Coast of Hawaiʻi.
Killer Whale
These killer whales were recorded off the coast of Hawaiʻi Island producing a series of low and high-pitched whistles to communicate with other adult and juvenile members of their pod. Killer whales are relatively rare in Hawaiʻi.
Melon-Headed Whale

Mystery Cetacean
Sounds of an unknown cetacean recorded in Saipan on August 2015. The main signal starts at 37 Hz with harmonics up to 415 Hz and lasting between 2-4 seconds.
Pilot Whale
Pilot whales often travel in larger pods and can be very vocally active, producing both echolocation clicks and low-pitched whistles. Their whistles have a squeaky quality similar to slowly letting air out of a balloon. They also produce burst pulses that are a repetitive series of pulsed sounds used in communication and hunting.
Rough-Toothed Dolphin
Rough-toothed dolphins produce whistles with "stepped" upward sweeping segments. Echolocation clicks give them the ability to explore their environment and search for prey. These sounds were recorded using a towed array behind the ship offshore of Maui.
Sperm Whale
Sperm whales produce low frequency echolocation clicks. This example of the sperm whale's "usual clicks" was recorded in December 2015 off of Saipan. These "clicks" are used for navigation and prey location during their long (~45 minutes), deep (500-1500 meter) foraging dives.