Offshore Wind Farms Could Disturb Marine Mammal Behavior

Offshore Wind Farms Could Disturb Marine Mammal Behavior

As the number and size of offshore turbines increase, so does the possible disruption to aquatic life.

Media Contact:
Larry Frum
AIP Media
301-209-3090
media@aip.org

DENVER, May 26, 2022 – When an offshore wind farm pops up, there is a period of noisy but well-studied and in most cases regulated construction. Once the turbines are operational, they provide a valuable source of renewable energy while emitting a constant lower level of sound that has not been fully investigated.

Frank Thomsen, of DHI, will discuss how this constant noise may impact wildlife in his presentation, “Operational underwater sound from future offshore wind turbines can affect the behavior of marine mammals.” The session will take place May 26 at 4:25 p.m. Eastern U.S. as part of the 182nd Meeting of the Acoustical Society of America at the Sheraton Denver Downtown Hotel.

Thomsen and colleagues reviewed published sound levels from operational wind farms to identify trends with turbine size. In general, the larger the turbine, the higher the noise emissions.

However, newer wind farms using quieter driving technology can to a certain extent cancel out the impact of larger turbines. Older gear box technology reaches disruptive levels for marine mammals up to 6.3 kilometers away. In contrast, newer direct drive turbines are expected to only impact animal behavior within a 1.4-kilometer radius.

“It is very unlikely that operational noise will lead to any injury or even hearing impairment, but behavioral changes could be a concern, as our study shows,” Thomsen said. “It’s possible that impact zones of individual turbines overlap, but that still does not mean that the wind farm is a no-go area for marine life. We see harbor porpoises frequently swimming in the vicinity of turbines.”

The long-term consequences of this noise on wildlife are still largely unknown. The impact could depend on the number of turbines and their overlapping affected areas.

In theory, the sound can lead to behavior changes in marine mammals and mask calls from whales, but harbor porpoises are frequently seen swimming in the vicinity of wind farms in Europe, so it may not be as simple as it seems.

“Since offshore wind farms have a relatively long lifespan, and there will be many of them, the potential impacts should not be overlooked,” said Thomsen. “The point of our work is to raise awareness.”

———————– MORE MEETING INFORMATION ———————–
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WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

Explosions Help Probe Elusive Atmospheric Waves

Explosions Help Probe Elusive Atmospheric Waves

Infrasound pulses from munitions plant explosions used to study gravity waves, atmospheric events

Media Contact:
Larry Frum
AIP Media
301-209-3090
media@aip.org

DENVER, May 25, 2022 – Infrasound waves can probe some of the most complex weather patterns hidden to normal observations, but finding a powerful enough source of infrasound waves can be a challenge unless there is a munitions factory nearby.

During the 182nd Meeting of the Acoustical Society of America, Stephen Arrowsmith, from Southern Methodist University, will discuss a method for using infrasound pulses from detonated munitions to probe atmospheric phenomena. His presentation, “The use of infrasound from repeating explosion sequences in Oklahoma to probe the atmosphere,” will take place May 25 at 10:55 a.m. Eastern U.S. at the Sheraton Denver Downtown Hotel.

Infrasound waves are acoustic waves at frequencies too low for humans to hear, but they can be invaluable for studying atmospheric phenomena. One example is gravity waves, which are small-scale waves in the atmosphere driven by buoyancy. These waves are small and transient, making them challenging to study with traditional methods. Infrasound waves have the speed and resolution to track those gravity waves.

“The sound that we record propagates upward into the atmosphere and is refracted back down to the ground,” said Arrowsmith. “The information they provide on the upper atmosphere can tell us about the winds aloft, and these can affect the weather at the ground.”

These infrasound waves need to be strong enough to reach the atmosphere and bounce back, which requires a sizeable source. Fortunately for Arrowsmith, an Oklahoma munitions factory routinely sets off large explosions multiple times per day. He and his team set up detectors in the area around the factory to measure infrasound reflections from the troposphere and stratosphere.

They were able to use the data to study short-term atmospheric fluctuations and tie those fluctuations to gravity waves and other events. They then compared their data across multiple days to study longer-term trends and compare those to meteorological models.

Arrowsmith intends this result to serve as a demonstration of the power of infrasound to probe the atmosphere and study some of its more elusive elements. He hopes infrasound could one day be used as a tool to better understand and predict weather patterns.

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASASPRING22
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

Snap, Crackle, Pop: Healthy Coral Reefs Brimming with Noise

Snap, Crackle, Pop: Healthy Coral Reefs Brimming with Noise

Monitoring their soundscape can provide a long term, nonintrusive, inexpensive method for tracking the state of reefs around the world

Media Contact:
Larry Frum
AIP Media
301-209-3090
media@aip.org

DENVER, May 25, 2022 – A healthy coral reef is loud. Like a busy city, the infrastructure leads to more organisms and activity, and more background noise. Every time an invertebrate drags their hard shell over the coral, or a fish takes a bite of its food, they add to the soundscape.

Vocal fish, whales, and dolphins occasionally interrupt with louder grunts and calls. Altogether, the hundreds of thousands of animals living in the reef sound like static on the radio, or the snap, crackle, and pop of a bowl of Rice Krispies as you pour milk on the cereal, when the coral reef is healthy. The sound changes for reefs that are not healthy, becoming quieter and less diverse.

Lauren Freeman, of the U.S. Naval Undersea Warfare Center Newport, will present experiment results of passively acoustically monitoring coral reefs to get a snapshot of their health at the 182nd Meeting of the Acoustical Society of America at the Sheraton Denver Downtown Hotel. The presentation, “Coral Reef & Temperate Coastal Soundscape Features Evident in Directional and Omnidirectional Passive Acoustic Time Series,” will take place May 25 at 11:35 a.m. Eastern U.S.

Passive acoustic monitoring of coral soundscapes offers a long-term, nonintrusive, and inexpensive way to track the state of reefs around the world, which are threatened by humanity via fishing, pollution, and climate change.
Compared to healthy reefs, degraded coral communities don’t have as rich or diverse of a soundscape. There tend to be fewer fish calls and more high frequency noise from algae photosynthesizing and releasing bubbles of oxygen, which ring out as they rise through the water.

“There is a natural competition between corals and macroalgae on all coral reefs. In most cases with a dying or degraded reef, the macroalgae is winning and covers a lot more of the surface,” said Freeman. “On a pristine reef, you would see very little macroalgae, and a lot of herbivorous fish that help eat the macroalgae.”

Freeman and her team deployed an acoustic array to monitor reefs off the coast of Hawaii. They compared these results to similar data from Bermuda and New England. Interestingly, Hawaii and Bermuda both showed a characteristic reef evening chorus, where the sound levels increased immediately prior to sunset. The New England reef underwent similar changes near dusk.

“Almost every time I conduct an experiment, we learn more about the complexities and intricacies of ambient biological soundscapes,” said Freeman. “It’s so exciting to continue to discover more about ocean ecosystems.”

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASASPRING22
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

Turning Hearing Aids into Noise-Canceling Devices

Turning Hearing Aids into Noise-Canceling Devices

Assistive listening devices can filter out noise from loudspeakers, improving clarity

Media Contact:
Larry Frum
AIP Media
301-209-3090
media@aip.org

DENVER, May 25, 2022 – People with hearing aids and other assistive listening devices often struggle at crowded events, because the various sources of sound make it difficult to make out any one of them clearly.

During the 182nd Meeting of the Acoustical Society of America, Ryan M. Corey, from the University of Illinois at Urbana-Champaign, will discuss his technique to improve hearing aid performance by actively canceling out unwanted sounds from speaker systems. His presentation, “Turn the music down! Repurposing assistive listening broadcast systems to remove nuisance sounds,” will take place May 25 at 1:45 p.m. Eastern U.S. at the Sheraton Denver Downtown Hotel.

For someone using an assistive listening device in a crowded place, it might make little difference whether the device is on or off. Nearby conversation directed at the user might be drowned out by distant conversation between other people, ambient noise from the environment, or music or speech piped through a loudspeaker system.

Corey and his colleagues worked to eliminate at least one source of noise, the one emanating from loudspeakers or other broadcast systems. By pairing the hearing aid with the broadcast system, the researchers can cancel out whatever is being broadcast and leaving the user free to enjoy nearby conversation.

“This project is a form of selective noise cancellation,” said Corey. “Noise-canceling headphones, like the kind that are popular for airplanes, are designed to cancel out everything. In this system, we only want to cancel a specific sound, like the music playing over the speakers, but let other sounds through.”

This approach is designed to be versatile and seamless. It should work for any venue, indoor or outdoor, where a loudspeaker or broadcast system is present. and should remove only the broadcast noise while preserving other nearby sounds just as the listener would normally hear them.

In the future, Corey hopes to combine this technology with arrays of microphones to give wearers of assistive listening devices even more control over which sounds they can listen to.

“My research is devoted to making hearing technology work better in noisy environments, usually by adding more microphones that can pick up sound from far away,” said Corey. “Most of my research focuses on those technologies, and they could be combined with this system to both remove noise and enhance specific talkers.”

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASASPRING22
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

On Mars, NASA’s Perseverance Rover’s Playlist Like No Other

On Mars, NASA’s Perseverance Rover’s Playlist Like No Other

Microphones on the rover capture, characterize sounds from red planet’s atmosphere

Media Contact:
Larry Frum
AIP Media
301-209-3090
media@aip.org

DENVER, May 25, 2022 – Since NASA’s Perseverance rover landed on Mars, its two microphones have recorded hours of audio that provide valuable information about the Martian atmosphere.

Baptiste Chide, of Los Alamos National Lab, will discuss the importance of this acoustical information in the presentation, “Mars soundscape: Review of the first sounds recorded by the Perseverance microphones,” at the 182nd Meeting of the Acoustical Society of America on May 25 at 3:45 p.m. Eastern U.S.at the Sheraton Denver Downtown Hotel.

After more than a year of recording on the surface, the team reduced the data to a Martian playlist that features about five hours of sounds. Most of the time, Mars is very quiet. Sounds are 20 decibels lower than on Earth for the same source, and there are few natural noises except for the wind.

“It is so quiet that, at some point, we thought the microphone was broken!” said Chide.

However, after listening carefully to the data, the group uncovered fascinating phenomena. There was a lot of variability in the wind, and the atmosphere could abruptly change from calm to intense with rapid gusts. By listening to well-characterized and intentional laser sparks, Perseverance calculated the dispersion of the sound speed, confirming a theory that high-frequency sounds travel faster than those at low frequencies.

“Mars is the only place in the solar system where that happens in the audible bandwidth because of the unique properties of the carbon dioxide molecule that composes the atmosphere,” said Chide.

The red planet’s seasons impact its soundscape. As carbon dioxide freezes in the polar caps during winter, the density of the atmosphere changes and the environment loudness varies by about 20%. That molecule also attenuates high-pitched sounds with distance.

Perseverance continues to collect audio recordings as it moves across different regions of Mars. Chide believes this technique will be even more informative on planets and moons with denser atmospheres, such as Venus and Titan, where sound waves interact more strongly and propagate farther.

———————– MORE MEETING INFORMATION ———————–
USEFUL LINKS
Main meeting website: https://acousticalsociety.org/asa-meetings/
Technical program: https://eventpilotadmin.com/web/planner.php?id=ASASPRING22
Press Room: https://acoustics.org/world-wide-press-room/

WORLDWIDE PRESS ROOM
In the coming weeks, ASA’s Worldwide Press Room will be updated with additional tips on dozens of newsworthy stories and with lay language papers, which are 300 to 500 word summaries of presentations written by scientists for a general audience and accompanied by photos, audio and video. You can visit the site during the meeting at https://acoustics.org/world-wide-press-room/.

PRESS REGISTRATION
We will grant free registration to credentialed journalists and professional freelance journalists. If you are a reporter and would like to attend, contact AIP Media Services at media@aip.org. For urgent requests, staff at media@aip.org can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America (ASA) is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.