02798nas a2200241 4500008004100000022001400041245006300055210005900118260001600177300001300193490000600206520211400212653001702326653001102343653001602354653001802370653001502388653002102403100001702424700002502441700002102466856006902487 1996 eng d a0952-462200aTHE MECHANISM OF TUNING OF THE MOLE CRICKET SINGING BURROW0 aMECHANISM OF TUNING OF THE MOLE CRICKET SINGING BURROW cJan-01-1996 a81 - 1170 v73 a

1. Experimental and theoretical studies on the acoustics of the singing burrow of the mole cricket Gryllotalpa australis are reported.


2. The burrow typically consists of a bulb about 26 mm long and 20 mm in diameter, connected through a constriction of diameter about 10 mm to a flaring horn with length about 40 mm and equivalent mouth diameter about 34 mm. The mouth geometry of the burrow differs from one species to another, and the aperture may be either single, double or even multiple. The end of the bulb opposite the horn connects to a narrow exit tunnei of diameter about 8 mm and length up to 1 m. The singing cricket positions itself close to the constriction between the bulb and the horn and produces a song with a frequency around 2.5 kHz.


3. Measurements of sound pressure within the burrow when it is excited by an external sound source at the song frequency show a pressure minimum at the constriction and an amplitude and phase distribution that is consistent with resonance of the burrow at its second modal frequency. The burrow is approximately three-quarters of a wavelength long at this frequency. The same result is obtained when the burrow is excited by a dipole source located near the constriction.


4. Non-parametric model calculations confirm this conclusion and also give broad agreement with the measured response curves over a frequency range from about 1.5 to 5 kHz. The calculated curves indicate an additional resonance at about 1.2 kHz associated with the first mode of the burrow—the Helmholtz or Klipsch resonance—which is apparently not utilised by the insect. This detail is consistent with earlier measurements, and is also supported by measured responses reported here that show an increase in sound pressure with decreasing frequency below 2 kHz as predicted by the model.


5. The measured performance of the burrow is broadly consistent with the model. According to the model, the burrow geometry is close to optimal for maximal sound power radiation.

10abioacoustics10aburrow10aGryllotalpa10amole crickets10aresonators10asound production1 aDAWS, A., G.1 aBennet-Clark, H., C.1 aFLETCHER, N., H. uhttp://www.tandfonline.com/doi/abs/10.1080/09524622.1996.975332101137nas a2200205 4500008004100000022001400041245006200055210006000117260002000177300001400197490000600211520054400217653000600761653001100767653001900778653001400797653002400811100002500835856007100860 1999 eng d a0952-462200aWHICH QS TO CHOOSE: QUESTIONS OF QUALITY IN BIOACOUSTICS?0 aWHICH QS TO CHOOSE QUESTIONS OF QUALITY IN BIOACOUSTICS cFeb-04-20122001 a351 - 3590 v93 a

Two Q factors are in common use in bioacoustics: Q, the Quality Factor and Q10 dB. The usage, definitions and separate application of these two terms can be traced back for more than 30 years. The two terms provide different measurements of the sharpness of tuning of e.g. acoustic systems. The two terms have been used in separate contexts and they measure different things. In view of the confusion that arises from the shared use of the letter Q, it is important that whichever Q is used is defined clearly in all publications.

10aQ10aQ10 dB10aQuality factor10aresonance10asharpness of tuning1 aBennet-Clark, H., C. uhttps://www.tandfonline.com/doi/full/10.1080/09524622.1999.975340802062nas a2200229 4500008004100000022001400041245007600055210006900131260001300200300001100213490000800224520135300232653002401585653001701609653001201626653002001638653001401658653002401672100002501696700002401721856008701745 2002 eng d a0022-094900aTicking of the clockwork cricket: the role of the escapement mechanism.0 aTicking of the clockwork cricket the role of the escapement mech c2002 Mar a613-250 v2053 a

The 'clockwork cricket' model for cricket sound production suggests that the catch-and-release of the file of one forewing by the plectrum on the opposite wing act as an 'escapement' to provide the phasic impulses that initiate and sustain the vibration of the resonant regions of the wings from which the sounds are produced. The action of the escapement produces the familiar ticking sound of clocks. The higher-frequency components of the songs of twelve species of cricket were analysed after removing the dominant low-frequency components and amplifying the remaining higher-frequency components. In normal song pulses of all species, the higher-frequency components showed a close phase-locking to the waveform of the dominant frequency, but the amplitude of the higher-frequency components did not correlate with that at the dominant frequency. Anomalous pulses occurred spontaneously in the songs of several species: multimodal, interrupted or curtailed pulses are described. In all of these, the anomalous pulse envelope was associated with changes in the amplitude and/or instantaneous frequency of the higher-frequency components of the sound. A model of the escapement suggests that the frequency of the residual components of the song depends on the symmetry of action of the plectrum on the teeth of the file.

10aanimal vocalization10aanimal wings10aAnimals10aescape reaction10aGryllidae10aspecies specificity1 aBennet-Clark, H., C.1 aBailey, Winston, J. uhttps://bio.acousti.ca/content/ticking-clockwork-cricket-role-escapement-mechanism00479nas a2200109 4500008004100000245009700041210006900138300001400207490000800221100002500229856011500254 1984 eng d00aA particle velocity microphone for the song of small insects and other acoustic measurements0 aparticle velocity microphone for the song of small insects and o a459–4630 v1081 aBennet-Clark, H., C. uhttps://bio.acousti.ca/content/particle-velocity-microphone-song-small-insects-and-other-acoustic-measurements01379nas a2200157 4500008004100000022001400041245009000055210006900145260001600214300001400230490000800244520087700252100002501129700001401154856005301168 1978 eng d a0028-083600aRegularity versus irregularity in specific songs of closely-related drosophilid flies0 aRegularity versus irregularity in specific songs of closelyrelat cFeb-02-1978 a442 - 4440 v2713 a

The songs of most insect species are stereotyped and show regular rhythms which can be readily defined and described. In such cases, closely related species produce songs which differ in rhythmic structure, carrier frequency, or combinations of these parameters. We have examined the songs produced during courtship of the sibling drosophilid fly species Zaprionus tuberculatus, Z. sepsoides and Z. mascariensis which are known from morphometric and chromosomal evidence to be closely related. Drosophilid songs are produced by wing beating and normally consist of a regular series of similar mono- or polycyclic sound pulses with carrier frequencies of 150 to 500 Hz and pulse periods of 8 to 250 ms (for review, see ref. 9). Some species produce more than one type of song, and the pulsed song may be interrupted by protracted bursts of constant frequency tone.

1 aBennet-Clark, H., C.1 aLeroy, Y. uhttp://www.nature.com/doifinder/10.1038/271442a003493nas a2200133 4500008004100000245007000041210006500111300001200176490000800188520307700196100002503273700001303298856004803311 1998 eng d00aSound radiation by the bladder cicada Cystosoma saundersii0 aSound radiation by the bladder cicada iCystosoma saundersiii a701-7150 v2013 a

Male Cystosoma saundersii have a distended thin-walled abdomen which is driven by the paired tymbals during sound production. The insect extends the abdomen from a rest length of 32-34 mm to a length of 39-42 mm while singing. This is accomplished through specialised apodemes at the anterior ends of abdominal segments 4-7, which cause each of these intersegmental membranes to unfold by approximately 2 mm. 

The calling song frequency is approximately 850 Hz. The song pulses have a bimodal envelope and a duration of approximately 25 ms; they are produced by the asynchronous but overlapping action of the paired tymbals. The quality factor Q of the decay of the song pulses is approximately 17. 

The abdomen was driven experimentally by an internal sound source attached to a hole in the front of the abdomen. This allowed the sound-radiating regions to be mapped. The loudest sound-radiating areas are on both sides of tergites 3-5, approximately 10 mm from the ventral surface. A subsidiary sound-radiating region is found mid-ventrally on sternites 4-6. Sound is radiated in the same phase from all these regions. As the abdomen was extended experimentally from its resting length to its maximum length, the amplitude of the radiated sound doubled and the Q of the resonance increased from 4 to 9. This resonance and effect are similar at both tergite 4 and sternite 5. 

Increasing the effective volume of the abdominal air sac reduced its resonant frequency. The resonant frequency was proportional to 1/(check)(total volume), suggesting that the air sac volume was the major compliant element in the resonant system. Increasing the mass of tergite 4 and sternites 4-6 also reduced the resonant frequency of the abdomen. By extrapolation, it was shown that the effective mass of tergites 3-5 was between 13 and 30 mg and that the resonant frequency was proportional to 1/(check)(total mass), suggesting that the masses of the tergal sound-radiating areas were major elements in the resonant system.

The tymbal ribs buckle in sequence from posterior (rib 1) to anterior, producing a series of sound pulses. The frequency of the pulse decreases with the buckling of successive ribs: rib 1 produces approximately 1050 Hz, rib 2 approximately 870 Hz and rib 3 approximately 830 Hz. The sound pulse produced as the tymbal buckles outwards is between 1.6 and 1.9 kHz. Simultaneous recordings from close to the tymbal and from tergite 4 suggest that the song pulse is initiated by the pulses produced by ribs 2 and 3 of the leading tymbal and sustained by the pulses from ribs 2 and 3 of the second tymbal.

An earlier model suggested that the reactive elements of the abdominal resonance were the compliance of the abdominal air sac volume and the mass of the abdomen undergoing lengthwise telescoping. The present work confirms these suggestions for the role of the air sac but ascribes the mass element to the in-out vibrations of the lateral regions of tergites 3-5 and the central part of sternites 4-6.

1 aBennet-Clark, H., C.1 aYoung, D uhttp://jeb.biologists.org/content/201/5/70102469nas a2200121 4500008004100000245004600041210004200087300001200129490000800141520212500149100002502274856004802299 1987 eng d00aThe Tuned Singing Burrow of Mole Crickets0 aTuned Singing Burrow of Mole Crickets a383-4090 v1283 a

During burrow digging by the mole cricket Scapteriscus acletus Rehn and Hubbard, the burrow is enlarged and shaped in a series of digging cycles, each lasting 1–2min, and song chirps are produced after every cycle. The song becomes up to 18 dB louder and acoustically purer during burrow building. The shape of the song pulse envelope changes so that its average power density becomes greater and its build-up and decay become more gradual.

The forewings show a single resonance of the harp (Cu 1 cell) regions at 2.5-3.0 kHz: the normal song carrier frequency is 2.5-2.7kHz. Removal of the outer parts of the forewings does not affect the radiated sound power.

The singing burrow has an exponential horn opening at the soil surface and an internal bulb. The calculated cut-off frequency of the horn is 1–34 kHz and that of the first resonance is 2.5-2.7 kHz. The volume of the bulb is close to that required to tune the throat: obliteration of the burrow bulb causes a substantial decrease in the radiated sound pressure levels before singing ceases.

The horn mouth acts as a finite sound source, with large acoustic reactance. The acoustics of the burrow were measured with a small doublet source inserted at the position at which the cricket sings. At this position, the burrow resonates at 2.75-3 kHz, with a quality factor (Q), measured both by the - 3 dB bandwidth and by the build-up and decay of tone bursts, of 2.5-2.7. The sound pressure produced by the doublet source is up to 24 dB louder when it is in the burrow than when it is in free air. Further in or out from the insect's singing position, the effective gain of the burrow is reduced and other resonances and anti-resonances are observed. Obliteration of the burrow bulb reduces the effective gain of the burrow by 6–10 dB and the burrow ceases to resonate at 2.75 kHz.

It is proposed that the tuned burrow acts as a resistive load on the vibrating harps, so allowing good coupling between the small wings and the surrounding medium while allowing a pure carrier frequency to be radiated.

1 aBennet-Clark, H., C. uhttp://jeb.biologists.org/content/128/1/38302759nas a2200133 4500008004100000245006000041210005800101300001200159490000800171520236000179100002502539700001302564856004802577 1992 eng d00aA MODEL OF THE MECHANISM OF SOUND PRODUCTION IN CICADAS0 aMODEL OF THE MECHANISM OF SOUND PRODUCTION IN CICADAS a123-1530 v1733 a

1. Dried cicada bodies of the species Cyclochila australasiae and model cicadas made from a miniature earphone driving a plastic cavity were used to study the acoustics of sound production in male cicadas.

2. A model cicada with shape and dimensions similar to those of the abdomen of a male C. australasiae resonates at the natural song frequency of the species (4.3 kHz). The abdominal air sac of C. australasiae also resonates at frequencies close to the natural song frequency when excited by external sounds. In an atmosphere of chlorofluorocarbon (CFC) gas, the resonant frequency is lowered in keeping with the decrease in velocity of sound in the CFC gas.

3. At the model's resonant frequency, the driving earphone dissipates more electrical power with the cavity attached than without the cavity. The cavity of the model cicada acts as a narrow-band acoustic acceptance filter, tuned to the natural song frequency.

4. When the miniature earphone emits brief clicks, mimicking those produced by the natural tymbal mechanism, the model cicada produces sound pulses that vary in duration and shape according to the number and timing of the clicks. A coherent train of two or three resonant clicks results in a long slowly-decaying sound pulse similar to that in the natural song.

5. The natural song frequency can be predicted from the dimensions of the abdominal cavity and the tympana in C. australasiae using a simple equation for the resonant frequency of a Helmholtz resonator. This equation also predicts the song frequency of Macrotristria angularis and Magicicada cassini, but it fails with the low-frequency song of Magicicada septendecim. This discrepancy can be accounted for by the unusually thick tympana of M. septendecim, which tend to lower the resonant frequency of the system.

6. We conclude that the abdomen of male cicadas forms a Helmholtz resonator, the components of which are the large air sac as the cavity and the tympana as the neck of the resonator. We suggest that cicada sound production depends on the coupling of two resonators, that of the tymbal and that of the abdominal air sac, from which sound is radiated through the tympana. The coupled resonator system would produce the long sound pulses required for stimulating a sensitive sharply tuned auditory organ.

1 aBennet-Clark, H., C.1 aYoung, D uhttp://jeb.biologists.org/content/173/1/12301229nas a2200145 4500008004100000022001400041245006300055210006200118260001300180300000900193490000600202520076400208100002500972856008600997 1990 eng d a0169-534700aDo the song pulses of Drosophila show cyclic fluctuations?0 aDo the song pulses of Drosophila show cyclic fluctuations c1990 Mar a93-70 v53 a

Following analysis of the song of two Drosophila species, Kyriacou and Hall in 1980 described a rhythmic variation in the intervals between sound pulses. This rhythmicity was species specific and various mutants also showed characteristic song-period rhythmicity. Recent attempts by Ewing and by Crossley to confirm the existence of the rhythms, using essentially similar methods, have failed; Kyriacou and Hall have since ascribed these failures to differences in technique and methods of measurement between them and their critics, and re-affirm that the rhythmicity they described exists. In view of the controversy surrounding the existence of song-period rhythmicity, a body of work on the genetics of this behaviour must be viewed with caution.

1 aBennet-Clark, H., C. uhttps://bio.acousti.ca/content/do-song-pulses-drosophila-show-cyclic-fluctuations03995nas a2200145 4500008004100000022001400041245009300055210006900148260000900217300001200226490000800238520352300246100002503769856005503794 1997 eng d a1477-914500aTymbal mechanics and the control of song frequency in the cicada Cyclochila australasiae0 aTymbal mechanics and the control of song frequency in the cicada c1997 a1681-940 v2003 a

The anatomy of the tymbal of Cyclochila australasiae was re-described and the mass of the tymbal plate, ribs and resilin pad was measured. The four ribs of the tymbal buckle inwards in sequence from posterior to anterior. Sound pulses were produced by pulling the tymbal apodeme to cause the tymbal to buckle inwards. A train of four sound pulses, each corresponding to the inward buckling of one rib, could be produced by each inward pull of the apodeme, followed by a single pulse as the tymbal buckled outwards after the release of the apodeme. Each preparation produced a consistent sequence of pulses. Each of the pulses produced had its maximum amplitude during the first cycle of vibration. The waveform started with an initial inward-going rarefaction followed by a larger outward compression, followed by an approximately exponential decay, as is typical of a resonant system. The mean dominant frequencies of the pulses produced during the inward movement were 4.37, 4.19, 3.92 and 3.17 kHz respectively. The pulse produced during the outward movement had a mean resonant frequency of 6.54 kHz. This suggests that the mass-to-stiffness ratio that determines the resonant frequencies of the various pulses differs from pulse to pulse. If succeeding pulses followed rapidly, the next pulse tended to start on the inward-going half-cycle of its predecessor and to produce a coherent waveform. Coherence was lost if the preceding pulse had decayed to below approximately one-tenth of its peak amplitude. When the tymbal plate was loaded by a 380 µg wire weight, the resonant frequency of all sound pulses was reduced. Pulses produced later in the inward buckling sequence were less affected by the loading than earlier ones. This suggests that the effective mass determining the resonance in the later pulses is greater than that in the earlier pulses. The frequency of the pulses produced in the outward movement was affected most, suggesting that the mass involved was less than that in any of the pulses produced by the inward movement. The quality factor, Q, of the pulses produced by the inward buckling of the unloaded tymbal was approximately 10. For the outward buckling, Q was approximately 6. The Q of loaded tymbals was higher than than that of unloaded tymbals. The Q of the resonances varied approximately as the reciprocal of the resonant frequency. Experimental removal of parts of the tymbal showed that the thick dorsal resilin pad was an important elastic determinant of the resonant frequency, but that the mass and elasticity of the tymbal ribs were also determinants of the resonant frequency. The major element of mass is the tymbal plate. The integrity of the tymbal ribs was essential if the buckling movement were to occur. The force required to cause inward buckling of the tymbal was approximately 0.25 N. The force required to hold the tymbal in the buckled-in position was approximately 0.05 N. This asymmetry in the tymbal compliance, together with the different masses involved in inward and outward buckling, may account for the difference between the resonant frequencies of the inward-going and outward-going clicks. The tymbal appears to act as an energy storage mechanism that releases energy as the tymbal ribs buckle inwards in sequence. Each pulse provides a large initial impulse to the abdominal resonator, followed by a sustaining resonant vibration at, or close to, the song frequency. Subsequent pulses maintain the coherent resonance of the song pulse.

1 aBennet-Clark, H., C. uhttp://jeb.biologists.org/content/200/11/1681.long02247nas a2200157 4500008004100000022001400041245009400055210006900149260001300218300001200231490001600243520173700259100002501996700001302021856005502034 1999 eng d a1477-914500aTransduction of mechanical energy into sound energy in the cicada Cyclochila australasiae0 aTransduction of mechanical energy into sound energy in the cicad c1999 Jul a1803-170 v202 (Pt 13)3 a

The anatomy of the paired tymbal muscles of Cyclochila australasiae was described. Force-distance relationships of the sound-producing in-out cycle of tymbal movement were measured. The largest forces were measured when the push occurred at the apodeme pit on the tymbal plate at angles similar to the angles of internal pull of the tymbal muscle. Initially, inward movement was opposed by the elasticity of the tymbal, which stored energy. At a mean force of 0. 38 N after a mean inward strain of 368 microm, the tymbal ribs buckled, the mean energy release being 45.1 microJ. The energy release occurred over 2-10 ms in three or four sound-producing steps as successive tymbal ribs buckled inwards. After the ribs had buckled, the force decreased to a mean value of 0.17 N. The force returned to zero during the outward movement, during which the tymbal ribs buckled outwards. The mean energy dissipated in the outward movement was 32.8 microJ. During contraction, the tymbal muscle produced mean values for the peak active force of 0.31 N over 295 microm, which gave mean values for the area of the work loops of 47.0 microJ. The calling song of C. australasiae had a mean pulse rate of 234 Hz (117 Hz for each side of the insect). The peak power to mean power ratio for the songs was 8.51:1 (+9.30 dB). Measurements of the sound field around tethered insects and of the peak power to mean power ratio of the songs gave values for the mean power of the song of 3.15-7 mW; these correspond to an energy per song pulse of 13.5-30 microJ. Previously reported mean values are 3. 15 mW for protest song and 5.1 mW for calling song. The efficiency of transduction of mechanical energy into sound energy is between 18 and 46 %.

1 aBennet-Clark, H., C.1 aDaws, AG uhttp://jeb.biologists.org/content/202/13/1803.long03638nas a2200157 4500008004100000022001400041245005400055210005000109260000900159300001200168490000800180520318300188100001303371700002503384856007103409 1995 eng d a1477-914500aThe role of the tymbal in cicada sound production0 arole of the tymbal in cicada sound production c1995 a1001-200 v1983 a

1. The tymbal of Cyclochila australasiae consists of a biconvex membrane bearing alternating long and short ribs anteriorly and an irregularly shaped tymbal plate posteriorly. These sclerotised regions are coupled together by the surrounding highly flexible cuticle, which contains resilin. Dorsally, there is a thick pad of resilin, which functions as a spring, returning the tymbal to the out position and maintaining the stress on the long ribs. 2. Contraction of the tymbal muscle causes the tymbal plate to swing inwards, acting as a lever so that the surface of the tymbal moves through more than twice the distance of muscle shortening. This produces an inward movement and twisting of the dorsal ends of the long ribs, which then buckle in sequence, with each rib undergoing a sudden deformation from a convex to a V-shaped profile. Buckling takes place at the rib's weakest point, which is the narrow, highly sclerotised mid-region. 3. Inward buckling of the tymbal generates a loud click with a dominant frequency around 4 kHz. Resonances close to 4 kHz can be demonstrated in a buckled-in tymbal when driven by internal sound or by vibration at the tymbal plate. These resonances occur in sealed cicadas and those in which the abdominal air sac has been opened at both its anterior and posterior ends, which shows that the resonances are not due to the air sac; the tymbal itself is a resonant system. The maximum amplitude of tymbal vibration occurs at the V-shaped dimples in the centre of the long ribs. 4. When the tymbal plus abdominal air sac system is driven by vibration at the tymbal plate, the Q3dB of the sound radiated through the tympana is about 12.5, which is approximately the sum of those of the tymbal (Q=9.3) and of the air sac (Q=3.4) resonators. When the tymbal is not loaded by the air sac, i.e. in the sealed cicada and open cicada preparations, the Q3dB of its resonance is higher, between 13 and 20. 5. The click produced as the tymbal pops out is over 20 dB quieter than the in-click and has a dominant frequency around 6 kHz. When driven in the resting position, resonances are found close to 6 kHz but there is only a weak general vibration of the ribs and tymbal plate. When the tymbal is pushed in gradually, the resonant frequency changes from about 5.5 kHz to about 4.3 kHz as the tymbal buckles inwards. The left and right tymbals of the same insect may differ slightly in their acoustic properties. 6. As the tymbal buckles inwards, it displaces a volume of approximately 6 µl into the abdominal air sac volume of about 2 ml. The resulting sound pressure inside the air sac attains peak values of 155­159 dB SPL; the root mean square values are 141­144 dB SPL. The mean peak value just outside the tympana is 148.5 dB SPL. 7. Overall, the present work supports and extends our earlier model of cicada sound production: the tymbal click provides a coherent resonant source that drives the abdominal resonator, from which sound is radiated via the tympana. At the same time, the system provides the pressure transformation between muscle power and sound power that is desirable for efficient sound radiation.

1 aYoung, D1 aBennet-Clark, H., C. uhttps://bio.acousti.ca/content/role-tymbal-cicada-sound-production03301nas a2200241 4500008004100000022001400041245010100055210006900156260001300225300001200238490000800250520258400258653001402842653002402856653001202880653001402892653001602906653001402922100002402936700002502960700001902985856005503004 2001 eng d a0022-094900aAcoustics of a small Australian burrowing cricket: the control of low-frequency pure-tone songs.0 aAcoustics of a small Australian burrowing cricket the control of c2001 Aug a2827-410 v2043 a

For most insects, size determines the call frequency. This paper describes the acoustics of a small brachypterous cricket (Rufocephalus sp.; body length 9.6 mm) producing a call with a carrier frequency of approximately 3.2 kHz from a subterranean burrow. Crickets such as Gryllus campestris are approximately twice this length and produce a call frequency close to 5 kHz. The burrow of Rufocephalus opens via a small hole with a diameter of 3.2 mm. The neck of the hole at approximately 1.4 mm depth opens to a vertical two-part burrow with an upper vase-shaped chamber 16.1 mm in height with a diameter of 9.4 mm. This top chamber connects via a 6.4mm high (diameter 5.2 mm) neck to a more irregular chamber approximately 18 mm high with a width of approximately 11 mm. The walls of the top chamber neck and of the upper part of the lower chamber are smooth and appear to be sealed with saliva. The song has a mean centre frequency of 3.2 kHz and is made up of variable-length trills of pulses of mean duration 15.8 ms. Many song pulses had smooth envelopes and their frequency did not vary by more than +/-40Hz from the centre frequency, with a relative bandwidth Q-3dB of over 50. Other pulses showed considerable amplitude and frequency modulation within the pulse. When driven by external sound, burrows resonated at a mean frequency of 3.5 kHz with a mean quality factor Q of 7.4. Natural-size model burrows resonated at similar frequencies with similar Q values. One cricket, which had previously called from its own burrow at 2.95 kHz, sang at 3.27 kHz from a burrow that resonated at the same frequency. Life-size model burrows driven by external sound resonated at similar frequencies to the actual burrows; models three times life size resonated at one-third of this frequency. In all models, the sound pressure was more-or-less constant throughout the top chamber but fell rapidly in the neck of the burrow; the phase of the sound was effectively constant in the top chamber and neck and fell through approximately 180 degrees in passing from the neck into the lower chamber. A numerical model of the sound flow from region to region gave essentially similar results. A resonant electrical model fed from a high-impedance source with discrete tone bursts at different frequencies showed similar amplitude and frequency modulation to the various types of song pulses that were observed. It is suggested that the high purity of the songs results from close entrainment of the sound-producing mechanism of the insect's wings to the sharply resonant burrow.

10aacoustics10aanimal vocalization10aAnimals10aAustralia10aenvironment10aGryllidae1 aBailey, Winston, J.1 aBennet-Clark, H., C.1 aFletcher, N, H uhttp://jeb.biologists.org/content/204/16/2827.long04773nas a2200205 4500008004100000022001400041245007600055210006900131260001300200300001200213490000800225520411800233653002504351653001704376653001204393653001404405653002404419100002504443856009904468 2003 eng d a0022-094900aWing resonances in the Australian field cricket Teleogryllus oceanicus.0 aWing resonances in the Australian field cricket Teleogryllus oce c2003 May a1479-960 v2063 a

The anatomy and mechanics of the fore-wings of the Australian cricket Teleogryllus oceanicus were examined to study how resonances of the wings were excited, to model the interactions between the two wings during sound production, to account for the frequency changes that occur within the pulses and to determine the variation in sound amplitude during the pulses. Sound is produced after raising the wings by closing the right wing over the left; the plectrum of the left wing engages and releases teeth on the file on the underside of the right wing. The mean number of teeth on the right file is 252; the teeth are more closely spaced in the posterior part of the file, which is engaged at the start of the song pulses. The anterior part of the file is separated from the base of the harp by a short flexible region. The dorsal field of the wing, in which the harp is situated, is largely mechanically isolated from the driving veins of the lateral field, except for a cross vein at the apex of the harp. The harps of the two wings did not differ significantly in area but the plectrum of the left wing was significantly longer and wider than that of the right wing. The posterior edge of the plectrum has a radius of approximately 0.5 micro m, which allows it to engage the 20 micro m-tall teeth of the file. The plectrum is separated from the wing by a 0.5 micro m-thick crescent that allows it to twist lengthways and thus disengage the file teeth. The sigmoid shape of the file allows the plectrum to engage teeth over most of the length of the file. The calling song of T. oceanicus consists of a chirp of four similar pulses followed by a trill of pairs of pulses. The dominant frequency of all pulses is approximately 4.8 kHz but cycle-by-cycle analysis suggests that the different types of pulse are produced by wing-closing movements through different arcs. Free resonances of the left wing occurred at 4.56 kHz [quality factor (Q)=25.1] and of the right wing at 4.21 kHz (Q=23.9). Driven by loud sound, maximum vibration of the harp was seen at approximately 4.5 kHz; at lower sound levels, the vibration was confined to the cross-veins of the harp that extend distally from the file. Resonances of the left wing driven by vibration of the same wing, either at the plectrum or on the anal area, occurred at similar frequencies to those of the songs and had similar Qs but were approximately anti-phase, demonstrating that movement of the plectrum (e.g. by the file teeth) causes an opposite movement of the harp. When the right wing was driven directly on the file, the resonant frequency was 5.88 kHz but, when driven on the file via a length of the left file and the left plectrum, it was 4.83 kHz. The amplitude of the vibration increased from the posterior end of the file to the middle then fell towards the anterior end of the file. Pushing a left plectrum across the middle of the right file produced trains of damped sound pulses at 4.82 kHz (Q=23.4). Clicks excited from the anterior end of the file had lower frequencies. The resonances excited from both the left wing via its plectrum and from the right wing when driven via the left plectrum were similar in frequency to that of the song. The resonance of the dorsal field persisted after ablation of the harp but the mean resonant frequency increased 1.12-fold with a similar Q to the intact wing. Droplets of water on the distal end of the harp or proximal part of the dorsal field raised the resonant frequency. The resonant frequency was lowered by the addition of weights to the harp or the file; the factor of the decrease suggested that the mass of the resonant system was approximately 1.4 mg, which accords with the mass of the harp plus file plus anal area of the wing (left wing, 1.27 mg; right wing, 1.15 mg) but is far heavier than the harp (0.22 mg). An earlier suggestion that the harp is the resonator is not supported; instead, it is proposed that the major elastic component of the resonant system is the file plus 1st anal vein and that the mass component is the combined mass of the file, anal area and harp.

10aanimal communication10aanimal wings10aAnimals10aGryllidae10asound spectrography1 aBennet-Clark, H., C. uhttps://bio.acousti.ca/content/wing-resonances-australian-field-cricket-teleogryllus-oceanicus00476nas a2200121 4500008004100000245012500041210006900166260001600235300001400251490000700265100002500272856005700297 1970 eng d00aA new French mole cricket, differing in song and morphology from Gryllotalpa gryllotalpa L. (Orthoptera: Gryllotalpidae)0 anew French mole cricket differing in song and morphology from Gr cJan-12-1970 a125 - 1320 v391 aBennet-Clark, H., C. uhttp://doi.wiley.com/10.1111/syen.1970.39.issue-9-1000422nas a2200109 4500008004100000245007000041210006600111300001200177490000700189100002500196856009100221 1970 eng d00aThe Mechanism and Efficiency of Sound Production in Mole Crickets0 aMechanism and Efficiency of Sound Production in Mole Crickets a619-6520 v521 aBennet-Clark, H., C. uhttps://bio.acousti.ca/content/mechanism-and-efficiency-sound-production-mole-crickets