Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bats show ability to change their ear shapes, making their hearing more flexible

15.11.2011
"Certain bats can deform the shapes of their ears in a way that changes the animal's ultrasonic hearing pattern. Within just one tenth of a second, these bats are able to change their outer ear shapes from one extreme configuration to another," said Rolf Müller, associate professor of mechanical engineering at Virginia Tech.

Müller and his students wrote a paper on their work that is appearing this week in Physical Review Letters, a prestigious peer-reviewed journal of the American Physical Society. The students are: Li Gao of Shandong, China, a Ph.D. student with Müller, and Sreenath Balakrishnan of Thrissur, Kerala, India, a master's candidate with Virginia Tech's Department of Mechanical Engineering, as well as Weikai He and Zhen Yan, of the School of Physics at Shandong University.

Müller explained the significance of their work, saying, "In about 100 milliseconds, this type of bat can alter his ear shape significantly in ways that would suit different acoustic sensing tasks."

By comparison, "a human blink of an eye takes two to three times as long. As a result of these shape changes, the shape of the animals' spatial hearing sensitivity also undergoes a qualitative change," Müller added.

Bats are flying mammals most well known for their abilities to navigate and pursue their prey in complete darkness. By emitting ultrasonic pulses and listing to the returning echoes, the animals are able to obtain detailed information on their surroundings. Horseshoe bats, in particular, can use their sonar systems to maneuver swiftly through dense vegetation and identify insect prey under difficult conditions.

Acting as biosonar receiving antennas, the ears of bats perform a critical function in bringing about these ultrasonic sensing capabilities.

Using a combination of methods that included high-speed stereo vision and high-resolution tomography, the researchers from Virginia Tech and Shandong University have been able to reconstruct the three-dimensional geometries of the outer ears from live horseshoe bats as they deform in these short time intervals.

Using computer analysis of the deforming shapes, the researchers found that the ultrasonic hearing spotlights associated with the different ear configurations could suit different hearing tasks performed by the animals. Hence, the ear deformation in horseshoe bats could be a substrate for adapting the spatial hearing of the animals on a very short time scale.

The research piggybacks earlier work led by Müller and reported this spring in the Institute of Physics' journal Bioinspiration and Biometrics. That study provided key insights into the various shapes of bat ears among the different species, and illustrated how the differences could affect how their navigation systems worked.

The National Natural Science Foundation of China, Shandong University, the Shandong Taishan Fund, and the China Scholarship Council supported the most recent work.

The collaboration between Shandong University and Virginia Tech started with Müller's opening of a new international laboratory based at the Chinese facility in 2010. The new laboratory focuses on bio-inspired research. In the past, the lab was used by an interdisciplinary group of researchers from the University of Utah, North Carolina State University, and University of California Los Angeles to conduct experiments on the extraordinary capabilities of bats to generate high-powered ultrasonic pulses.

Müller's aspiration in teaching is to bridge the gap between disciplines, especially between biology and engineering.

Müller's research is focused on the understanding of how the most capable biological sensory systems can achieve their best performances. His recent achievements include: providing the first physical explanation for the role of a prominent flap seen in mammalian ears in 2004; discovery of a novel helical scan in the ear directivity of a bat in 2006; discovery of frequency-selective beam-forming by virtue of resonances in noseleaf furrows of a bat, an entirely new bioacoustic paradigm in 2006; establishing the first immediate and quantitative characterization of the spatial information created by a mammal's outer ear in 2007; and now uncovering the acoustic effect of non-rigid ear deformations in bats.

Müller received the Friendship Award of the People's Republic of China, considered China's highest honor for "foreign experts who have made outstanding contributions to the country's economic and social progress." Also, he received a Top Ten Scholars Award from Shandong University in 2006, Tuebingen University's 1999 Dissertation Award, and held a NATO Post-Doctoral Fellowship from 1998 until 2000.

He holds a patent on a method for frequency-driven generation of a multi-resolution decomposition of the input to wave-based sensing arrays.

Lynn Nystrom | EurekAlert!
Further information:
http://www.vt.edu

More articles from Physics and Astronomy:

nachricht SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

nachricht New survey hints at exotic origin for the Cold Spot
26.04.2017 | Royal Astronomical Society

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>