@article {57643,
	title = {Low-pass filters and differential tympanal tuning in a paleotropical bushcricket with an unusually low frequency call},
	year = {2013},
	abstract = {<p>Low-frequency sounds are advantageous for long-range acoustic signal transmission, but for small animals they constitute a challenge for signal detection and localization. The efficient detection of sound in insects is enhanced by mechanical resonance either in the tracheal or tympanal system before subsequent neuronal amplification. Making small structures resonant at low sound frequencies poses challenges for insects and has not been adequately studied. Similarly, detecting the direction of long-wavelength sound using interaural signal amplitude and/or phase differences is difficult for small animals. Pseudophylline bushcrickets predominantly call at high, often ultrasonic frequencies, but a few paleotropical species use lower frequencies. We investigated the mechanical frequency tuning of the tympana of one such species, Onomarchus uninotatus, a large bushcricket that produces a narrow bandwidth call at an unusually low carrier frequency of 3.2 kHz. Onomarchus uninotatus, like most bushcrickets, has two large tympanal membranes on each fore-tibia. We found that both these membranes vibrate like hinged flaps anchored at the dorsal wall and do not show higher modes of vibration in the frequency range investigated (1.5\&ndash;20 kHz). The anterior tympanal membrane acts as a low-pass filter, attenuating sounds at frequencies above 3.5 kHz, in contrast to the high-pass filter characteristic of other bushcricket tympana. Responses to higher frequencies are partitioned to the posterior tympanal membrane, which shows maximal sensitivity at several broad frequency ranges, peaking at 3.1, 7.4 and 14.4 kHz. This partitioning between the two tympanal membranes constitutes an unusual feature of peripheral auditory processing in insects. The complex tracheal shape of O. uninotatus also deviates from the known tube or horn shapes associated with simple band-pass or high-pass amplification of tracheal input to the tympana. Interestingly, while the anterior tympanal membrane shows directional sensitivity at conspecific call frequencies, the posterior tympanal membrane is not directional at conspecific frequencies and instead shows directionality at higher frequencies.</p>
},
	keywords = {auditory, katydid, laser vibrometry, Onomarchus uninotatus, Orthoptera, pseudophylline, tettigoniid, trachea, tympanum},
	doi = {10.1242/jeb.078352},
	url = {http://jeb.biologists.org/cgi/doi/10.1242/jeb.078352https://syndication.highwire.org/content/doi/10.1242/jeb.078352},
	author = {Rajaraman, K. and Mhatre, N. and Jain, M. and Postles, M. and Rohini Balakrishnan and Daniel Robert}
}
@article {47305,
	title = {Convergent Evolution Between Insect and Mammalian Audition},
	journal = {Science},
	volume = {338},
	year = {2012},
	month = {Apr-15-20122141},
	pages = {968 - 971},
	issn = {0036-8075},
	doi = {10.1126/science.1225271},
	url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1225271https://syndication.highwire.org/content/doi/10.1126/science.1225271},
	author = {Fernando Montealegre-Zapata and Jonsson, T. and Robson-Brown, K. A. and Postles, M. and Daniel Robert}
}
@article {11172,
	title = {Wing stridulation in a Jurassic katydid (Insecta, Orthoptera) produced low-pitched musical calls to attract females},
	journal = {Proceedings of the National Academy of Sciences},
	volume = {109},
	year = {2012},
	month = {Jun-03-2012},
	pages = {3868 - 3873},
	abstract = {<p>Behaviors are challenging to reconstruct for extinct species, particularly the nature and origins of acoustic communication. Here we unravel the song of Archaboilus musicus Gu, Engel and Ren sp. nov., a 165 million year old stridulating katydid. From the exceptionally preserved morphology of its stridulatory apparatus in the forewings and phylogenetic comparison with extant species, we reveal that A. musicus radiated pure-tone (musical) songs using a resonant mechanism tuned at a frequency of 6.4 kHz. Contrary to previous scenarios, musical songs were an early innovation, preceding the broad-bandwidth songs of extant katydids. Providing an accurate insight into paleoacoustic ecology, the low-frequency musical song of A. musicus was well-adapted to communication in the lightly cluttered environment of the mid-Jurassic forest produced by coniferous trees and giant ferns, suggesting that reptilian, amphibian, and mammalian insectivores could have also heard A. musicus\&$\#$39; song.</p>
},
	keywords = {biological asymmetry, biomechanics, bushcricket, call evolution, Tettigoniidae},
	issn = {0027-8424},
	doi = {10.1073/pnas.1118372109},
	url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1118372109},
	author = {Gu, J.-J. and Fernando Montealegre-Zapata and Daniel Robert and Engel, M. S. and Qiao, G.-X. and Ren, D.}
}
