@article {57622,
	title = {Tuning the drum: the mechanical basis for frequency discrimination in a Mediterranean cicada},
	year = {2006},
	abstract = {<p>Cicadas are known to use sound to find a mate. While the mechanism employed by male cicadas to generate loud calling songs has been described in detail, little information exists to explain how their ears work. Using microscanning laser Doppler vibrometry, the tympanal vibrations in the cicada Cicadatra atra are measured in response to acoustic playbacks. The topographically accurate optical measurements reveal the vibrational behaviour of the anatomically complex tympanal membrane. Notably, the tympanal ridge, a distinct structural element of the tympanum that is a link to the receptor cells, undergoes mechanical vibrations reminiscent of a travelling wave. In effect, the frequency for which the maximum deflection amplitude is observed regularly decreases from the apex to the base of the ridge. It is also shown that whilst female ears are mechanically tuned to the male\&$\#$39;s song, the male\&$\#$39;s tympanum is only partially tuned to its own song. This study establishes the presence of a peripheral auditory mechanism that can potentially process auditory frequency analysis. In view of the importance of acoustic signalling in cicadas, this unconventional tympanal mechanism may be employed in the context of species recognition and sexual selection.</p>
},
	keywords = {biomechanics, Cicada, frequency discrimination, hearing, travelling wave, tympanum},
	author = {Sueur, Jerome and James F.C. Windmill and Daniel Robert}
}
@article {47922,
	title = {When males whistle at females: complex FM acoustic signals in cockroaches},
	journal = {Naturwissenschaften},
	volume = {93},
	year = {2006},
	month = {Jan-10-2006},
	pages = {500 - 505},
	abstract = {<p>Male cockroaches of the species Elliptorhina chopardi expel air through a pair of modified abdominal spiracles during courtship. This air expulsion simultaneously produces air and substrate-borne vibrations. We described and compared in details these two types of vibrations. Our analysis of the air-borne signals shows that males can produce three categories of signals with distinct temporal and frequency parameters. \&ldquo;Pure whistles\&rdquo; consist of two independent harmonic series fast frequency modulated with independent harmonics that can cross each other. \&ldquo;Noisy whistles\&rdquo; also possess two independent voices but include a noisy broad-band frequency part in the middle. Hiss sounds are more noise-like, being made of a broad-band frequency spectrum. All three call types are unusually high in dominant frequency (\&gt;5 kHz) for cockroaches. The substrate-borne signals are categorised similarly. Some harmonics of the substrate-borne signals were filtered out, however, making the acoustic energy centered on fewer frequency bands. Our analysis shows that cockroach signals are complex, with fast frequency modulations and two distinct voices. These results also readdress the question of what system could potentially receive and decode the information contained within such complex sounds.</p>
},
	keywords = {acoustic communication, Cockroach, courtship, Elliptorhina chopardi, frequency modulations, two-voice system},
	issn = {0028-1042},
	doi = {10.1007/s00114-006-0135-9},
	url = {http://link.springer.com/10.1007/s00114-006-0135-9},
	author = {Sueur, Jerome and Aubin, Thierry}
}
