Nav: Home

Bush-crickets' ears unlock the science to developing revolutionary hearing sensors

February 11, 2020

New research has found that bush-crickets' ear canals have evolved to work in the same way as mammals' ears to amplify sound and modulate sound pressure - and the findings could help scientists make better acoustic sensors for human use.

Bush-crickets are insects that depend on acoustic communication for survival, with the males singing to attract distant females. They have very small 'ears' in their forelegs, which work in a similar way to humans with an outer, middle and inner ear, and many species have transparent 'skins', enabling scientists to measuring ear processes.

An international team of sensory biologists and mathematicians found that the insects' horn-shaped outer ear, called the acoustic trachea tube, captures sound in the same way as mammals' ear canals by amplifying and transforming the pressure waves, which are then passed along to the surface of the eardrum to provide the animal with directional hearing.

Until now, the mechanism responsible for such changes in sound pressure levels which affects directional hearing has been unknown. The findings could revolutionise how auditory devices identify the location or origin of a detected sound, aiding the challenging design of wireless acoustic sensor networks used for monitoring and surveillance purposes.

The team carried out the study on a species called Copiphora gorgonensis, which are found in the Colombian rainforest. They used 3D x-ray imaging to capture the structure of the bush-cricket's ears, coupled with mathematical analysis to determine how the sound worked inside the acoustic tube.

The research was part of a €1.9million European Research Council-funded project led by Professor Fernando Montealegre-Zapata, an entomologist specialising in sensory biology and biophysics at the University of Lincoln, UK. It was carried out in partnership with the University of Bristol, and University of Graz in Austria.

Dr Emine Celiker, a Research Fellow in numerical modelling in the School of Life Sciences at the University of Lincoln, conducted the study. She said: "The research is the first step in using combined experimental and mathematical techniques to determine the mechanism crickets use to hear their species' songs.

"Our findings provide a strong indication that the bush-cricket ear processes sound in the same way a mammal's does, making its study vital for the development of new auditory sensors. We were able to take recordings of the auditory process using laser doppler vibrometry which measures the vibrations of soundwaves on the surface of the ear canal.

"By applying mathematical modelling of the ears combined with real-life experiments, we also found that the ear canal filters out sound frequencies relevant to the species' survival, selectively amplifying only frequencies that are behaviourally relevant for the animals - like their mating song or the high-frequency calls of predatory bats.

"Traditionally it is well known that horns increase the volume of sound, and for bush-cricket hearing it has been suspected that this is also the case due to the geometry of its acoustic tube. We verified this after a thorough investigation of the processes involved in the sound amplification. The findings have huge potential to be applied in enhancing acoustic sensors such listening devices."

The findings have been published in Biophysical Journal.

University of Lincoln

Related Research Articles:

More Research News and Research Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at     You can read The Transition Integrity Project's report here.