02345nas a2200265   4500008004100000022001400041245013100055210006900186260002000255300001600275490000800291520145900299653002301758653001701781653001701798653002901815653002901844653003001873100002001903700002401923700002401947700002001971700002801991856006002019       2017                        eng d  a0022-094900aChamber music: an unusual Helmholtz resonator for song amplification in a Neotropical bush-cricket (Orthoptera, Tettigoniidae)0 aChamber music an unusual Helmholtz resonator for song amplificat  cSep-15-20172153  a2900 - 29070 v2203 a<p>Animals use sound for communication, with high-amplitude signals being selected for attracting mates or deterring rivals. High amplitudes are attained by employing primary resonators in sound producing structures to amplify the signal (e.g., avian syrinx). Some species actively exploit acoustic properties of natural structures to enhance signal transmission by using these as secondary resonators (e.g., tree-hole frogs). Male bush-crickets produce sound by tegminal stridulation and often use specialised wing areas as primary resonators. Interestingly, Acanthacara acuta, a Neotropical bush-cricket, exhibits an unusual pronotal inflation, forming a chamber covering the wings. It has been suggested that such pronotal chambers enhance amplitude and tuning of the signal by constituting a (secondary) Helmholtz resonator. If true, the intact system &ndash; when stimulated sympathetically with broadband sound &ndash; should show clear resonance around the song carrier frequency which should be largely independent of pronotum material, and change when the system is destroyed. Using laser Doppler vibrometry on living and preserved specimens, micro computed tomography, 3D printed models, and finite element modelling, we show that the pronotal chamber not only functions as a Helmholtz resonator due to its intact morphology but also resonates at frequencies of the calling song on itself, making song production a three-resonator system.</p>
10aacoustic resonator10abioacoustics10abush-cricket10afinite element modelling10alaser Doppler vibrometry10amicro computed tomography1 aJonsson, Thorin1 aBrown, Kate, Robson1 aSarria-S, Fabio, A.1 aWalker, Matthew1 aMontealegre-Z, Fernando  uhttp://jeb.biologists.org/lookup/doi/10.1242/jeb.160234