Abstract
Bushcrickets have a tonotopically organised hearing organ, the so-called crista acustica, in the tibia of the forelegs. This organ responds to a frequency range of about 5–80 kHz and lies behind the anterior tympanum on top of a trachea branch. We analyzed the sound-induced vibration pattern of the anterior tympanum, using a Laser-Doppler-Vibrometer Scanning microscope system, in order to identify frequency-dependent amplitude and phase of displacement. The vibration pattern evoked by a frequency sweep (4–79 kHz) showed an amplitude maximum which would correspond to the resonance frequency of an open tube system. At higher frequencies of about 30 kHz a difference in the amplitude and phase response between the distal and the proximal part of the tympanum was detected. The inner plate of the tympanum starts to wobble at this frequency. This higher mode in the motion pattern is not explained by purely acoustic characteristics of the tracheal space below the tympanum but may depend on the mechanical impedance of the tympanum plate. In accordance with a previous hypothesis, the tympanum moves over the whole tested frequency range in the dorso-ventral direction like a hinged flap with the largest displacement in its ventral part and no higher modes of vibration.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- CO2 :
-
Carbon dioxide
- DPOAE:
-
Distortion product otoacoustic emission
References
Bailey WJ (1991) Acoustic behaviour of insects: an evolutionary approach. Chapman and Hall, London
Bangert M, Kalmring K, Sickmann T, Stephen R, Jatho M, Lakes-Harlan R (1998) Stimulus transmission in the auditory receptor organs of the foreleg of bushcrickets (Tettigoniidae). I. The role of the tympana. Hear Res 115(1–2):27–38
Heinrich R, Jatho M, Kalmring K (1993) Acoustic transmission characteristics of the tympanal tracheae of bushcrickets (Tettigoniidae). II. Comparative studies of the tracheae of seven species. J Acoust Soc Am 93(6):3481–3489
Hill KG, Oldfield BP (1981) Auditory function in Tettigoniidae (Orthoptera: Ensifera). J Comp Physiol A 142:169–180
Hoffmann E, Jatho M (1995) The acoustic trachea of Tettigoniids as an exponential horn: theoretical calculations and bioacoustical measurements. J Acoust Soc Am 98(4):1845–1851
Kalmring K, Rössler W, Ebendt R, Ahi J, Lakes R (1993) The auditory receptor organs in the forelegs of bushcrickets: physiology, receptor cell arrangement, and morphology of the tympanal and intermediate organs of three closely related species. Zool Jb Physiol 97:75–94
Kalmring K, Rössler W, Unrast C (1994) Complex tibial organs in the forelegs, midlegs, and hindlegs of the bushcricket Gampsocleis gratiosa (Tettigoniidae): comparison of the physiology of the organs. J Exp Biol 270:155–161
Kleindienst H-U, Wohlers DW, Larsen ON (1983) Tympanal membrane motion is necessary for hearing in crickets. J Comp Physiol A 151:397–400
Lakes R, Schikorski T (1990) Neuroanatomy of tettigoniids. In: Bailey WJ, Rentz DCF (eds) The Tettigoniidae: biology systematics and evolution. Bathurst, Crawford House, pp 166–190
Larsen ON (1981) Mechanical time resolution in some insect ears. J Comp Physiol A 143:297–304
Lewis DB (1974) The physiology of the Tettigoniide ear. I. The implications of the anatomy of the ear to its function in sound reception. J Exp Biol 60:821–837
Michelsen A, Larsen ON (1978) Biophysics of the ensifera ear. I. Tympanal vibrations in the bushcrickets (Tettigoniidae) studied with laser vibrometry. J Comp Physiol A 123:193–203
Michelsen A, Heller KG, Stumpner A, Rohrseitz K (1994) A new biophysical method to determine the gain of the acoustic trachea in bushcrickets. J Comp Physiol A 175(2):145–151
Nityananda V, Balakrishnan R (2006) A diversity of songs among morphologically indistinguishable katydids of the genus Mecopoda (Orthoptera: Tettigoniidae) from Southern India. Bioacoustics 15:223–250
Nocke H (1975) Physical and physiological properties of the Tettigoniid (“grasshopper”) ear. J Comp Physiol A 100:25–57
Römer H, Bailey W (1998) Strategies for hearing in noise: peripheral control over auditory sensitivity in the bushcricket Sciarasaga quadrata (Austrosaginae: Tettigoniidae). J Exp Biol 201(7):1023–1033
Schuhmacher R (1975) Scanning-Electron-Microscope discrimination of the tympanal organ of Tettigoniidae (Orthoptera, Ensifera). Z Morphol Tiere 81:209–219
Schuhmacher R (1979) Zur funktionellen Morphologie des auditiven Systems der Laubheuschrecken (Orthoptera, Tettigoniidae). Entomol Gen 5:321–356
Shen J-X (1993) A peripheral mechanism for auditory directionality in the bushcricket Gampsocleis gratiosa: acoustic tracheal system. J Acoust Soc Am 94(3):1211–1217
Sickmann T, Kalmring K, Müller A (1997) The auditory–vibratory system of the bushcricket Polysarcus denticauda (Phaneropterinae, Tettigoniidae). I. Morphology of the complex tibial organs. Hear Res 104(1–2):155–166
Strauss J, Lakes-Harlan R (2008a) Neuroanatomy and physiology of the complex tibial organ of an atympanate ensiferan, Ametrus tibialis (Brunner von Wattenwyl, 1888) (Gryllacrididae, Orthoptera) and evolutionary implications. Brain Behav Evol 71(3):167–180
Strauss J, Lakes-Harlan R (2008b) Neuroanatomy of the complex tibial organ of Stenopelmatus (Orthoptera: Ensifera: Stenopelmatidae). J Comp Neurol A 511(1):81–91
Strauss J, Lakes-Harlan R (2009) The evolutionary origin of auditory receptors in Tettigonioidea: the complex tibial organ of Schizodactylidae. Naturwissenschaften 96(1):143–146
Acknowledgments
First and foremost, we would like to thank Prof. Dr. Ernst-August Seyfarth for his support and discussion and Dr. Bernhard Gaese for his support with the statistical procedures. We also thank Arun Palghat Udayashankar for programming and Edeltraut Thielen for technical assistance. This project is supported by a grant of the Deutsche Forschungsgemeinschaft (NO 841/1-1) and stipend from the Jürgen Manchot Stiftung, Ruth Moufang Fonds, Gleichstellungsfonds FB 15 Goethe University and Evangelisches Studienwerk. The performed experiments comply with the current laws of the country in which they were made.
Conflict of interest
The authors declare that they have no conflict of interest.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Nowotny, M., Hummel, J., Weber, M. et al. Acoustic-induced motion of the bushcricket (Mecopoda elongata, Tettigoniidae) tympanum. J Comp Physiol A 196, 939–945 (2010). https://doi.org/10.1007/s00359-010-0577-6
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00359-010-0577-6