The role of the tymbal in cicada sound production

1995 ◽  
Vol 198 (4) ◽  
pp. 1001-1020 ◽  
Author(s):  
D Young ◽  
H Bennet-Clark

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.

Author(s):  
Sandra Goutte ◽  
Matías I. Muñoz ◽  
Michael J. Ryan ◽  
Wouter Halfwerk

AbstractIn animal communication, receivers benefit from signals providing reliable information on signallers’ traits of interest. Individuals involved in conflicts, such as competition between rivals, should pay particular attention to cues that are ‘unfakeable’ by the senders due to the intrinsic properties of the production process. In bioacoustics, the best-known example of such ‘index signals’ is the relationship between a sender’s body size and the dominant frequency of their vocalizations. Dominant frequency may however not only depend on an animal’s morphology but also on the interaction between the sound production system and its immediate environment. Here, we experimentally altered the environment surrounding calling frogs and assessed its impact on the signal produced. More specifically, we altered water level, which forced frogs to float on the surface and tested how this manipulation affected the shuttling of air between the lungs and the vocal sac, and how this in turn impacted the calls’ dominant frequency. Our results show that frogs that are floating are able to fully inflate their lungs and vocal sacs, and that the associated change in airflow or air pressure is correlated with a decrease of call dominant frequency.


2002 ◽  
Vol 205 (5) ◽  
pp. 613-625 ◽  
Author(s):  
H. C. Bennet-Clark ◽  
Winston J. Bailey

SUMMARYThe ‘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.


2005 ◽  
Vol 83 (7) ◽  
pp. 721-737
Author(s):  
H Teffahi ◽  
B Guerin ◽  
A Djeradi

Knowledge of vocal tract area functions is important for the understanding of phenomena occurring during speech production. We present here a new measurement method based on the external excitation of the vocal tract with a known pseudo-random sequence, where the area function is obtained by a linear prediction analysis applied to the cross-correlation between the sequence and the signal measured at the lips. The advantages of this method over methods based on sweep-tones or white noise excitation are (1) a much shorter measurement time (about 100 ms) and (2) the possibility of speech sound production during the measurement. This method has been checked against classical methods through systematic comparisons on a small corpus of vowels. Moreover, it has been verified that simultaneous speech sound production does not perturb significantly the measurements. This method should thus be a very helpful tool for the investigation of the acoustic properties of the vocal tract in various cases for vowels.


2021 ◽  
pp. 25-29
Author(s):  
A. E. Barulin ◽  
S. V. Klauchek ◽  
A. E. Klauchek

Purpose of the study. To establish the relationship between neurophysiological status and the level of efficiency in young people with bruxism.Materials and methods. Two groups of 64 and 53 subjects (males and females) aged 20–35 years old with bruxism and non-bruxers were formed according to questionnaire results and physical examination. The level of efficiency was assessed by the results of sensorimotor tracking of a moving object (the ‘Smile’ model). Spectral analysis was performed for evaluation of the baseline electroencephalograms. Microsoft Excel and Statistica 10.0 programs were used for statistical data processing.Results. The level of efficiency was statistically significantly lower in the hardest test of Smile model among the individuals with bruxism (p < 0.05). The bruxers also demonstrated a significantly lower dominant frequency and maximum amplitude of alpha-rhythm (p < 0.05), and significantly higher dominant frequency of beta2 rhythm (p < 0.05). The dominant frequency and the maximum amplitude of the alpha-rhythm are parameters corresponding to significant coefficients of the regression analysis. A negative relationship was found between the degree of error during sensorimotor tracking and the frequency and amplitude of alpha-rhythm.Conclusion. Regression models present the relationship between the level of efficiency and the alpha-rhythm severity. The regression equations make it possible to determine the functional state of the subject using an electroencephalogram.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Thomas Wilkinson ◽  
Eleanor Gore ◽  
Jared Palmer ◽  
Luke Baker ◽  
Emma Watson ◽  
...  

Abstract Background and Aims Individuals living with CKD are characterised by adverse changes in physical function. Knowledge of the factors that mediate impairments in physical functioning is crucial for developing effective interventions that preserve mobility and future independence. Mechanical muscle power describes the rate of performing work and is the product of muscular force and velocity of contraction. Muscle power has been shown to have stronger associations with functional limitations and mortality than sarcopenia in older adults. In CKD, the role of mechanical muscle power is poorly understood and is overlooked as a target in many rehabilitation programmes, often at the expense of muscle mass or strength. The aims of this study were to 1) explore the prevalence of low absolute mechanical power, low relative mechanical power, and low specific mechanical power in CKD; and 2) investigate the association of mechanical power with the ability to complete activities of daily living and physical performance. Method Mechanical muscle power (relative, allometric, specific) was calculated using the sit-to-stand-5 (STS5) test as per previously validated equations. Legs lean mass was derived from regional analyses conducted using bioelectrical impedance analysis (BIA). Physical performance was assessed using two objective tests: usual gait speed and the ‘time-up-and-go’ (TUAG) test. Self-reported activities of daily living (ADLs) were assessed via the Duke Activity Status Index (DASI). Balance and postural stability (postural sway and velocity) was assessed using a FysioMeter. Sex-specific tertiles were used to determine low, medium and high levels of relative STS power and its main components. Results 102 participants with non-dialysis CKD were included (mean age: 62.0 (±14.1) years, n=49 males (48%), mean eGFR: 38.0 (±21.5) ml.min.1.73m2). The mean estimated relative power was 3.1 (±1.5) W.kg in females and 3.3 (±1.3) W.kg in males. Low relative power was found in 35/102 (34%) patients. Relative power was a significant independent predictor of self-reported ADLs (via the DASI) (B=.413, P=.004), and performance on the TUAG (B=-.719, P&lt;.001) and gait speed (B=.404, P=.003) tests. Skeletal muscle mass was not associated with the DASI or any of the objective function tests Conclusion Patients presenting with low muscle power would benefit from participation in appropriate interventions designed to improve the physiological components accounting for low relative muscle power. Assessment of power can be used to tailor renal rehabilitation programmes as shown in Figure 1. Incorporation of power-based training, a novel type of strength training, designed by manipulating traditional strength training variables and primarily movement velocity and training intensity may present the best strategy for improving physical function in CKD.


1991 ◽  
Vol 70 (3) ◽  
pp. 1215-1219 ◽  
Author(s):  
M. A. Martins ◽  
S. A. Shore ◽  
J. M. Drazen

We examined the role of substance P (SP) and neurokinin A (NKA) in the postmortem bronchoconstriction in guinea pig lungs using isolated lungs superfused via the trachea. Airway opening pressure (Pao) during superfusion was monitored and the superfusate collected for analysis of SP- and NKA-like immunoreactivities (SP-LI and NKA-LI, respectively). Peak Pao (39.0 +/- 3.9 cmH2O) was reached 10 min after starting superfusion; Pao decreased slowly thereafter, reaching only 9.9 +/- 2.2% of the peak value 2 h after starting superfusion (P less than 0.005); 12.6 +/- 2.6 and 34.0 +/- 9.7 fmol of SP-LI and NKA-LI, respectively, were found in the fraction corresponding to 10-20 min of superfusion. Recovered immunoreactivities decreased to 5.2 +/- 0.3 and 9.3 +/- 1.8 fmol of SP-LI and NKA-LI, respectively, in the fraction corresponding to 110-120 min of superfusion (P less than 0.05). Inhibition of neutral endopeptidase with thiorphan resulted in significantly greater increases in Pao (P less than 0.005) and augmentation of the recovery of SP-LI and NKA-LI (P less than 0.05 and P less than 0.001, respectively). Capsaicin treatment of animals 7-10 days before the removal of their lungs abolished the increase in Pao during superfusion and resulted in a significant decrease in the amount of SP-LI and NKA-LI recovered. Our data confirm that tachykinin release occurs during postmortem bronchoconstriction in guinea pig lungs and, furthermore, that tachykinin degradation by NEP modulates the intensity of this response.


Author(s):  
Maria Louis

Gender-based violence (GBV) has grown into a pandemic. It has spread its tentacles so far and wide that no country or community in the 21st century is immune from it. There are, of course, laws to prevent GBV and punish the perpetrators of GBV. But, the laws, in general, pathetically fail to yield the desired result and fail to play the role of an effective deterrent as lawmakers themselves, most often, become lawbreakers. It is well known that patriarchy has a vested interest in gender inequality, which is the root cause of GBV. The dominant gender, male, uses violence against all other genders, including female and third gender, as a lethal weapon to prove their muscle-power, pseudo-superiority, and enjoy what is not morally and ethically and legally right. GBV is undoubtedly a human right violation. However, in the land of nonviolence, India, marital rape, among others, is still legal. Things are slowly changing, and it gives hope.


2019 ◽  
Vol 124 ◽  
pp. 110631 ◽  
Author(s):  
Mikel L. Sáez de Asteasu ◽  
Nicolás Martínez-Velilla ◽  
Fabricio Zambom-Ferraresi ◽  
Álvaro Casas-Herrero ◽  
Robinson Ramirez-Vélez ◽  
...  

2020 ◽  
Vol 9 (1) ◽  
pp. 48-60
Author(s):  
Sajil C. K. ◽  
Achuthsankar S. Nair

Active noise control (ANC) systems are tailored for user-specific scenarios which are required in biomedical applications due to the physical restrictions in the placement of sensors and actuators. This study examines the role of spectral flatness of acoustic channels and room reflection coefficients in ANC performance. Each room has a unique characteristic response in transforming a source signal. By employing preliminary measurements and numerical simulation, the authors show that improved noise control is possible by optimizing room reverberation and spectral flatness of the secondary acoustic channel. This result has potential application in improving existing ANC systems in biomedical applications like fMRI.


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