Over three years
the hydrophones recorded 184 bowhead whale songs.
Kate Stafford of the University of Washington in Seattle and her colleagues planted
hydrophones in the Fram Strait between Greenland and Svalbard, halfway between Norway and the North Pole.
«We have
hydrophones in the Atlantic, the Arctic, off Greenland, in the Bering Sea and in the Antarctic now, and I am constantly amazed at the variety of sounds coming from the sea,» she says.
In May 1997,
hydrophones picked up the «Slowdown» sound.
Currently, detection of underwater sounds happens with
hydrophones, which have to be underwater.
The researchers measured the sound produced by the fish using an echo sounder (a sonar unit) and
a hydrophone (underwater microphone).
«The project installs a total of 40
hydrophones in the Baltic Sea.»
Just imagine a crack that lasts 1/10, 000 of a second but can be picked up by
hydrophones — and heard by other sperm whales — at a distance of 15 miles or more.
Drop
a hydrophone over the side of a boat in the middle of a school and you will hear, depending upon the species, anything from birdlike trills to whistles, squeaks, squawks, oinks, blats, and Bronx cheers.
The researchers of six countries bordering the Baltic Sea who participate in the BIAS project installed noise - measuring
hydrophones on the southern side of the Jussarö lighthouse near Tvärminne and in the Gulf of Finland between Helsinki and Tallinn.
Researchers endowed the observatory's six nodes with instruments that measure the ocean's changing temperature and chemistry, cameras that spy underwater creatures,
hydrophones that listen to passing whales and seismometers and tsunami detectors that measure hazards as they happen.
Questions remain, however, such as if seismometers are sufficient for remote monitoring or if the more accurate information provided by cabled
hydrophone arrays is worth the greater expense.
Tepp and colleagues at National Oceanic and Atmospheric Administration and USGS recently deployed
a hydrophone array in the Northern Mariana Islands.
Evidence of these eruptions showed up on distant seismometers, which measure waves passing through the ground to record earthquakes, and
hydrophone arrays that pick up underwater sound to detect covert nuclear detonations.
During the past several months, Gratta and his students have begun collecting data from seven of the array's 52
hydrophones.
Next he hopes to plug into the rest of
the hydrophones, start tallying the neutrinos, and begin to zero in on the strange, energetic objects that emit them.
The Navy wanted to know if hydrates under the seafloor were interfering with acoustic signals picked up by an underwater
hydrophone array used by the military to track Soviet subs.
Monitor endangered Pacific Northwest killer whales by detecting orca sounds and measuring noise levels using
hydrophones
As they recorded the whales with
a hydrophone at point - blank range, Gedamke sometimes heard a bizarre sound.
«The process of taking measurements in a carbonated beverage was more challenging than we expected, mainly because bubbles form on
the hydrophone itself and that can greatly affect the data that is collected,» said Spratt.
«When we came across the idea that bubbles play an important role in the quality of a sparkling wine, our first instinct was to drop
a hydrophone into a glass and see what kind of sound we can hear,» said Spratt.
To prevent from altering the properties of the champagne bubbles, researchers resorted to using a very small
hydrophone.
The researchers used a small boat to tow an array of underwater microphones, called
hydrophones, about 2 meters below the surface and recorded the sounds of individual dolphins identified by their dorsal fins.
But the CTBTO's stations have two sets of three
hydrophones separated by several kilometers, which — like a pair of human ears — allow listeners to get a fix on a sound's direction to within 0.5 °.
The US Navy deployed vast arrays of
hydrophones on the ocean floor during the cold war for anti-submarine warfare.
Meanwhile, it is unclear what other sources of
hydrophone data that could be used in the search exist in the region.
William Marks, a spokesman for the US Navy in Yokosuka, Japan, declined to comment on whether the United States had
hydrophones in the region.
«Using the three
hydrophones from the Cape Leeuwin station, it was possible to get a precise bearing that showed the signal came from the north - west.
To do this, the researchers use underwater microphones called
hydrophones on oceanographic moorings to listen for the sounds made by marine mammals.
Researchers at IMDEA Networks (Spain) in collaboration with University of Haifa (Israel) have developed an underwater acoustic system for the localization of marine mammals, underwater vehicles and other sound sources in the ocean, using no more than a single
hydrophone (basically an underwater microphone) as a receiver.
A boat can «mow the lawn» over a large area in a relatively short period of time, while stationary recorders on the seafloor have great temporal coverage, but they record only within a certain range of
the hydrophone,» said Selene Fregosi, a researcher at the Cooperative Institute for Marine Resources Studies, Oregon State University and National Oceanic and Atmospheric Administration in Newport, Oregon.
As conventional localization algorithms such as those used in GPS - like systems can not be directly ported to an underwater scenario, in this innovative system the localization is performed thanks to the incorporation of additional information about the environment surrounding the receiving
hydrophone.
Once their range of sounds is pinned down, an array of
hydrophones could be deployed around a reef to get an idea of the number, size and sex of lionfish living there.
Until recently, the tools required to study noise — underwater listening devices known as
hydrophones — were too expensive to be widespread.
They took advantage of a rare moment in 2009, when a video camera and
a hydrophone were floating 1,200 meters below sea level in the Pacific Ocean near Samoa, watching and listening as the West Mata Volcano blew up in several ways.
The sound blasts reflected from the boundaries between rock layers a few miles beneath the ocean floor were picked up by an five - mile - long «streamer,» or hose containing many
hydrophones, towed just beneath the surface behind the ship.
After the seismic survey, the Langseth returned to pick up 60 seismometers, leaving behind 20 broadband seismometers and
the hydrophones that will listen for a year to the reverberations from distant earthquakes, allowing the seismologists to map structures as deep as 60 miles beneath the surface.
Taking turns with his shipmates, Wiens swung bright - yellow ocean bottom seismometers and
hydrophones off the fantail, and lowered them gently to the water's surface, as the ship laid out a matrix of instruments for a seismic survey on the trench.
Between Jan. 26 and Feb. 9, working day and night, watch - on and watch - off, the Thompson laid down 80 ocean bottom seismometers and five
hydrophones.
Since then, a few scientists have tried to listen in, but Rountree and his team are the first to submerge
hydrophones in the deep ocean for the sole purpose of listening to fish.
Throughout the night and day that
the hydrophones were on the seafloor, they picked up what Rountree describes as «drumming» and «duck - like» noises.
The researchers handed the devices over to sea - bound fishers, who dropped
the hydrophones into a North Atlantic underwater canyon more than 600 meters (2,000 feet) deep.
He is interested in both natural and anthropogenic underwater sound and has worked extensively with
hydrophone arrays to characterize ship noise and marine mammal sound.
We provide an underwater
hydrophone on all of our Orca Water tours and will often stop to listen to the sounds the orcas make.
Some boats have
hydrophones so you can listen to their whale songs too.
We're always on the lookout for orca and carry
a hydrophone onboard to listen to this mammal's vocalizations.
One feature all our tours share is a group
hydrophone to listen to the orcas» underwater conversations.
When we encounter killer whales on the water, we often drop
a hydrophone into the water so we can listen to their vocalizations.
We carry
a hydrophone aboard the boat and can listen to the whale's vocalizations.
Best of all, tourists will be able to make full use of the provided
Hydrophone to hear the highly - coveted whale song.