The control of carrier frequency in cricket calls: a refutation of the subalar-tegminal resonance/auditory feedback model

2000 ◽  
Vol 203 (3) ◽  
pp. 585-596 ◽  
Author(s):  
K.N. Prestwich ◽  
K.M. Lenihan ◽  
D.M. Martin
Keyword(s):  
Resonant Frequency ◽  
Carrier Frequency ◽  
Auditory Feedback ◽  
Narrow Band ◽  
Variable Frequency ◽  
Low Density ◽  
Sound Pulse ◽  
Spectral Purity ◽  
Feedback Model ◽  
Gryllus Rubens

The subalar-tegminal resonance/auditory feedback hypothesis attempts to explain how crickets control the carrier frequency (f(C)), the loudness and the spectral purity of their calls. This model contrasts with the ‘clockwork cricket’ or escapement model by proposing that f(C) is not controlled by the resonance of the cricket's radiators (the harps) but is instead controlled neurally. It suggests that crickets are capable of driving their harps to vibrate at any frequency and that they use a tunable Helmholtz-like resonator consisting of the tegmina and the air within the subalar space to amplify and filter the f(C). This model predicts that f(C) is variable, that call loudness is related to tegminal position (and subalar volume) and that low-density gases should cause f(C) to increase. In Anurogryllus arboreus, f(C) is not constant and varied by as much as 0.8 % between pulses. Within each sound pulse, the average f(C) typically decreased from the first to the last third of a sound pulse by 9 %. When crickets called in a mixture of heliox and air, f(C) increased 1.07- to 1.14-fold above the value in air. However, if the subalar space were part of a Helmholtz-like resonator, then its resonant frequency should have increased by 40–50 %. Moreover, similar increases occurred in species that lack a subalar space (oecanthines). Experimental reduction of the subalar volume of singing crickets resulted neither in a change in f(C) nor in a change in loudness. Nor did crickets attempt to restore the subalar volume to its original value. These results disprove the presence of a subalar-tegminal resonator. The free resonance of freshly excised Gryllus rubens tegmina shifted by 1.09-fold when moved between air and a mixture of helium and air. Auditory feedback cannot be the cause of this shift, which is similar to the f(C) shifts in intact individuals of other species. Calculations show that the harp is 3.9-1.8 times more massive than the air that moves en masse with the vibrating harps. Replacing air with heliox-air lowers the mass of the vibrating system sufficiently to account for the f(C) shifts. These results re-affirm the ‘clockwork cricket’ (escapement) hypothesis. However, as realized by others, the harps should be viewed as narrow-band variable-frequency oscillators whose tuning may be controlled by factors that vary the effective mass.

Sound radiation by the bladder cicada cystosoma saundersii

1998 ◽  
Vol 201 (5) ◽  
pp. 701-715 ◽  
Author(s):  
H Bennet-Clark ◽  
D Young
Keyword(s):  
Resonant Frequency ◽  
Sound Production ◽  
Ventral Surface ◽  
Major Elements ◽  
Sound Pulse ◽  
Resonant System ◽  
Song Frequency ◽  
The Masses ◽  
Quality Factor Q ◽  
Sound Pulses

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. <P> 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. <P> 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. <P> 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. <P> 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. <P> 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.

scholarly journals Extreme-ultraviolet spectral purity and magnetic ion debris mitigation by use of low-density tin targets

2006 ◽  
Vol 31 (10) ◽  
pp. 1549 ◽  
Author(s):  
S. S. Harilal ◽  
M. S. Tillack ◽  
Y. Tao ◽  
B. O'Shay ◽  
R. Paguio ◽  
...  
Keyword(s):  
Extreme Ultraviolet ◽  
Low Density ◽  
Spectral Purity ◽  
Magnetic Ion ◽  
Debris Mitigation

Spectral purity and phase coherence of narrow-band noise in NbSe3

1982 ◽  
Vol 44 (8) ◽  
pp. 1179-1182 ◽  
Author(s):  
M. Weger ◽  
G. Grüner ◽  
W.G. Clark
Keyword(s):  
Narrow Band ◽  
Phase Coherence ◽  
Spectral Purity ◽  
Narrow Band Noise ◽  
Band Noise

Research on the Carrier Frequency Loss Characteristics of Induction Motor Fed with Variable Frequency Power

2014 ◽  
Vol 651-653 ◽  
pp. 840-843
Author(s):  
Yao Hui Wu ◽  
Cheng Fang Ji ◽  
Xiu Feng Meng
Keyword(s):  
Power Supply ◽  
Carrier Frequency ◽  
Frequency Conversion ◽  
Reference Value ◽  
Element Model ◽  
Variable Frequency ◽  
Joint Simulation ◽  
Simulation Calculation ◽  
Frequency Inverter ◽  
Frequency Power

The artical for the consumption problem caused by carrier frequency of motor with variable frequency power supply.According to the principle of frequency conversion,the frequency conversion power model has been established, which applied to finite element model of motor.Then they implement joint simulation calculation. It is concluded that the characteristics relationship between the carrier frequency and loss of motor when variable frequency power supply. The characteristic of relationship between the loss of the motor and the carrier frequency proved by experiment when the carrier frequency inverter power supply.It has reference value for the design of variable frequency motor, frequency conversion application and energy saving.

A Robust Transceiver for Narrow-Band Communications in Presence of Carrier Frequency Offset

2019 ◽  
Vol 111 (1) ◽  
pp. 565-580
Author(s):  
Mohammad H. Amerimehr ◽  
Mohsen Rezaee ◽  
Hamid Reza Dalaei
Keyword(s):  
Carrier Frequency ◽  
Carrier Frequency Offset ◽  
Narrow Band ◽  
Frequency Offset

scholarly journals Sound emission of solid surfaces through bubble layer

2021 ◽  
Vol 2119 (1) ◽  
pp. 012066
Author(s):  
I A Ogorodnikov
Keyword(s):  
Resonant Frequency ◽  
Open Resonator ◽  
Spectral Lines ◽  
Sound Pulse ◽  
Sound Emission ◽  
Field Radiation ◽  
Separate Line ◽  
Bubble Layer ◽  
Internal Properties ◽  
Sound Pulses

Abstract The analysis of the influence of a thin homogeneous bubble layer on sound emission from a solid surface is carried out. Sound pulses and monochromatic wave packets with a carrier frequency equal to the resonant frequency of the bubbles forming the bubble layer are considered. It is shown that the bubble layer transforms short sound pulses into wave sound packets and significantly reduces the amplitude of the emitted sound. The structure of a sinusoidal wave packet is transformed similarly. A long sound pulse is stored in the form of a pulse, its shape changes significantly. A homogeneous bubble layer near a solid radiating surface is an open resonator. The layer generates far-field radiation with spectral lines depending on the method of layer excitation and the internal properties of the bubble layer. The resonant frequency of the bubble is the limiting frequency in the spectrum, but it is not distinguished by a separate line.

scholarly journals Narrow-band emission with 0.5 to 3.5 Hz varying frequency in the background of the main phase of the 17 March 2013 magnetic storm

2016 ◽  
Vol 2 (4) ◽  
pp. 13-23
Author(s):  
Александр Потапов ◽  
Alexander Potapov ◽  
Борис Довбня ◽  
Boris Dovbnya ◽  
Дмитрий Баишев ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Storm ◽  
Carrier Frequency ◽  
Narrow Band ◽  
Vertical Component ◽  
Main Phase ◽  
Ion Fluxes ◽  
Emission Frequency ◽  
Band Emission ◽  
Generation Region

We present results of the analysis of an unusually long narrow-band emission in the Pc1 range with increasing carrier frequency. The event was observed against the background of the main phase of a strong magnetic storm caused by arrival of a high-speed solar wind stream with a shock wave in the stream head and a long interval of negative vertical component of the interplanetary magnetic field. Emission of approximately 9-hour duration had a local character, appearing only at three stations located in the range of geographical longitude λ=100–130 E and magnetic shells L=2.2–3.4. The signal carrier frequency grew in a stepped mode from 0.5 to 3.5 Hz. We propose an emission interpretation based on the standard model of the generation of ion cyclotron waves in the magnetosphere due to the resonant wave-particle interaction with ion fluxes of moderate energies. We suppose that a continuous shift of the generation region, located in the outer area of the plasmasphere, to smaller L-shell is able to explain both the phenomenon locality and the range of the frequency increase. A narrow emission frequency band is associated with the formation of nose-like structures in the energy spectrum of the ion fluxes penetrating from the geomagnetic tail into magnetosphere. We offer a possible speculative scenario of the processes leading to the generation of the observed emission. The scenario contains specific values of the generation region position, plasma density, magnetic field, and resonant proton energies. We discuss morphological differences of the emissions considered from known types of geomagnetic pulsations, and reasons for the occurrence of this unusual event.

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