Hearing with exceptionally thin tympana: Ear morphology and tympanal membrane vibrations in eneopterine crickets

In resting tethered locusts, the effect of slow changes in tracheal air pressure on peripheral auditory information processing was analysed. The tympanal membrane vibrations, the pressure inside the tracheal system and the summed activity of the auditory receptors were measured simultaneously. With the membrane in the resting position, laser vibrometry and Fast Fourier Transformation analysis of sound-induced membrane vibrations demonstrated characteristic power spectra at the attachment sites of the high-frequency and low-frequency receptors. The spectra were different above 9 kHz, but very similar in the range 29 kHz. During ventilation, tracheal pressure changed between -500 and 1500 Pa. This caused tympanal membrane peak-to-peak displacements in the range 7090 µm outwards and 2030 µm inwards, as measured by means of laser interferometry. For a quantitative analysis, sinusoidal tympanal membrane displacements with amplitudes such as those during natural ventilation could be induced by applying pressure to the tracheal system. There was a sigmoid relationship between the tracheal pressure and the corresponding membrane displacement. Outward displacements of the tympanal membrane at the attachment site of the elevated process (a-cells) attenuated sound-induced membrane vibrations in the ranges 210 kHz and 1422 kHz and increased them in the ranges 1014 kHz and 2225 kHz. At the pyriform vesicle (d-cells), the vibration sensitivity was reduced in the frequency range 214 kHz. Sensitivity was enhanced in the range 1425 kHz. As a consequence, the detection of acoustic signals was also influenced at the auditory receptor level. Tympanal membrane displacements during acoustic stimulation with 4 kHz sound pulses decreased the summed receptor response by approximately 15 dB. At 16 kHz, an increase of the response equivalent to 7 dB occurred. The effect on the response to white noise was intermediate.

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Differential transformation method for circular membrane vibrations

SERIES III - MATEMATICS, INFORMATICS, PHYSICS ◽

10.31926/but.mif.2019.61.12.2.12 ◽

2020 ◽

Vol 61(12) (2) ◽

pp. 333-350

Author(s):

Jaipong Kasemsuwan ◽

◽

Sorin Vasile Sabau ◽

Uraiwan Somboon ◽

◽

...

Keyword(s):

Transformation Method ◽

Differential Transformation Method ◽

Circular Membrane ◽

Differential Transformation ◽

Membrane Vibrations

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Faculty Opinions recommendation of Reticular lamina and basilar membrane vibrations in living mouse cochleae.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726634156.793522011 ◽

2016 ◽

Author(s):

Geoffrey A Manley

Keyword(s):

Basilar Membrane ◽

Living Mouse ◽

Membrane Vibrations

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Hearing from the ocean and into the river: the evolution of the inner ear of Platanistoidea (Cetacea: Odontoceti)

Paleobiology ◽

10.1017/pab.2021.11 ◽

2021 ◽

pp. 1-21

Author(s):

Mariana Viglino ◽

Maximiliano Gaetán ◽

Mónica R. Buono ◽

R. Ewan Fordyce ◽

Travis Park

Keyword(s):

Inner Ear ◽

High Frequency ◽

Sound Production ◽

Marine Species ◽

Late Oligocene ◽

Evolutionary Patterns ◽

Ear Morphology ◽

Cochlear Morphology ◽

First Time ◽

Hearing Abilities

Abstract The inner ear of the two higher clades of modern cetaceans (Neoceti) is highly adapted for hearing infrasonic (mysticetes) or ultrasonic (odontocetes) frequencies. Within odontocetes, Platanistoidea comprises a single extant riverine representative, Platanista gangetica, and a diversity of mainly extinct marine species from the late Oligocene onward. Recent studies drawing on features including the disparate tympanoperiotic have not yet provided a consensus phylogenetic hypothesis for platanistoids. Further, cochlear morphology and evolutionary patterns have never been reported. Here, we describe for the first time the inner ear morphology of late Oligocene–early Miocene extinct marine platanistoids and their evolutionary patterns. We initially hypothesized that extinct marine platanistoids lacked a specialized inner ear like P. gangetica and thus, their morphology and inferred hearing abilities were more similar to those of pelagic odontocetes. Our results reveal there is no “typical” platanistoid cochlear type, as the group displays a disparate range of cochlear anatomies, but all are consistent with high-frequency hearing. Stem odontocete Prosqualodon australis and platanistoid Otekaikea huata present a tympanal recess in their cochlea, of yet uncertain function in the hearing mechanism in cetaceans. The more basal morphology of Aondelphis talen indicates it had lower high-frequency hearing than other platanistoids. Finally, Platanista has the most derived cochlear morphology, adding to evidence that it is an outlier within the group and consistent with a >9-Myr-long separation from its sister genus Zarhachis. The evolution of a singular sound production morphology within Platanistidae may have facilitated the survival of Platanista to the present day.

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The Structure and Acoustic Properties of Aluminum Foams by Gas Injection Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.1049 ◽

2010 ◽

Vol 146-147 ◽

pp. 1049-1055

Author(s):

Xue Liu Fan ◽

Xiang Chen ◽

Yan Xiang Li

Keyword(s):

Sound Absorption ◽

Gas Injection ◽

Optical Microscope ◽

Absorption Efficiency ◽

Absorption Capacity ◽

Acoustic Properties ◽

Analytical Models ◽

Aluminum Foams ◽

Injection Method ◽

Membrane Vibrations

The acoustic properties of aluminum foams by gas injection method were studied experimentally. The micro and macro structure of aluminum foam with closed cells were observed by optical microscope (OM) and scanning electron microscope (SEM). The special structure of the closed-pores of the aluminum foams have leaded to good performance of the sound absorption based on three mechanisms: Helmholtz resonance, cell wall vibration and viscous and thermal effects. The effect of cell sizes, thickness of aluminum foams has been investigated and the cavity set at the back of the foam samples on the sound absorption efficiency of the foams has been measured. Analytical models of membrane vibrations were used to explain the sound absorption capacity of the foams.

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Energy Shaping Control of Electrostatic Membrane Vibrations

Volume 7B: 17th Biennial Conference on Mechanical Vibration and Noise ◽

10.1115/detc99/vib-8010 ◽

1999 ◽

Author(s):

Andreas Kugi ◽

Kurt Schlacher ◽

Manfred Kaltenbacher ◽

Reinhard Lerch

Keyword(s):

Nonlinear Distortion ◽

Supply Voltage ◽

Mathematical Formulation ◽

Voltage Source ◽

Membrane Electrode ◽

Closed Loop System ◽

Feedback Controllers ◽

Electrostatic Transducers ◽

Membrane Vibrations ◽

The Mathematical Model

Abstract A strong analytical mathematical formulation of electrostatic transducers is the necessary prerequisite for the design of feedback controllers. Based on the theory of Hamiltonian systems the mathematical model of a typical electrostatic transducer configuration with a moving membrane electrode and a rigid backplate electrode is derived. It is a well known fact that an increase in the sensitivity of the transducer often brings about also an increase in the nonlinear distortion and may occur a sticking of the membrane to the backplate electrode. In this paper, we propose a concept that gives a possible solution for these undesirable effects by using a controlled voltage source for the supply voltage of the transducer. The controller is designed by shaping the potential energy of the closed loop system. The change of the capacity of the transducer due to the motion of the membrane is considered as the sensor output.

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The morphology of the inner ear of squamate reptiles and its bearing on the origin of snakes

Royal Society Open Science ◽

10.1098/rsos.170685 ◽

2017 ◽

Vol 4 (8) ◽

pp. 170685 ◽

Cited By ~ 11

Author(s):

Alessandro Palci ◽

Mark N. Hutchinson ◽

Michael W. Caldwell ◽

Michael S. Y. Lee

Keyword(s):

Geometric Morphometrics ◽

Inner Ear ◽

Phylogenetic Signal ◽

Three Dimensional ◽

Lizard Species ◽

Squamate Reptiles ◽

Strong Affinity ◽

Ear Morphology

The inner ear morphology of 80 snake and lizard species, representative of a range of ecologies, is here analysed and compared to that of the fossil stem snake Dinilysia patagonica , using three-dimensional geometric morphometrics. Inner ear morphology is linked to phylogeny (we find here a strong phylogenetic signal in the data that can complicate ecological correlations), but also correlated with ecology, with Dinilysia resembling certain semi-fossorial forms ( Xenopeltis and Cylindrophis ), consistent with previous reports. We here also find striking resemblances between Dinilysia and some semi-aquatic snakes, such as Myron (Caenophidia, Homalopsidae). Therefore, the inner ear morphology of Dinilysia is consistent with semi-aquatic as well as semi-fossorial habits: the most similar forms are either semi-fossorial burrowers with a strong affinity to water ( Xenopeltis and Cylindrophis ) or amphibious, intertidal forms which shelter in burrows ( Myron). Notably, Dinilysia does not cluster as closely with snakes with exclusively terrestrial or obligate burrowing habits (e.g. scolecophidians and uropeltids). Moreover, despite the above similarities, Dinilysia also occupies a totally unique morphospace, raising issues with linking it with any particular ecological category.

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Study on the Intravenous Lung Assist Device (ILAD) Using PZT Actuators and PVDF Sensors

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.381-382.353 ◽

2008 ◽

Vol 381-382 ◽

pp. 353-356

Author(s):

Gi Beum Kim ◽

S.J. Kim ◽

Y.C. Lee ◽

C.U. Hong ◽

H.S. Kang ◽

...

Keyword(s):

Transfer Rate ◽

Semipermeable Membrane ◽

Gas Transfer ◽

Scaling Analysis ◽

Membrane Oxygenator ◽

Assist Device ◽

Dimensionless Groups ◽

Membrane Vibrations ◽

Insight Into ◽

Membrane Vibration

The purpose of this study was to investigate the effect of vibration device in gas transfer rate for usage as intravenous lung assist device. Specific attention was focused on the effect of membrane vibration. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on hemolysis. Scaling analysis was then used to infer the dimensionless groups that correlate the performance of a vibrated hollow tube membrane oxygenator. The experimental design and procedure are then given for a device for assessing the effectiveness of membrane vibrations. This ILAD is used to provide some insight into how wall vibrations might enhance the performance of an intravascular lung assist device. The time and the frequency response of PVDF sensor were investigated through various frequencies in the ILAD. In these devices, the flow of blood and the source of oxygen were separated by a semipermeable membrane allows oxygen to diffuse into and out of the f1uid, respectively. The results of experiments have shown vibrating ILAD performs effectively.

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