Directional hearing by mechanical coupling in the parasitoid fly Ormia ochracea

1996 ◽  
Vol 179 (1) ◽  
Author(s):  
D. Robert ◽  
R.N. Miles ◽  
R.R. Hoy

2000 ◽  
Author(s):  
C. Gibbons ◽  
R. N. Miles

Abstract A miniature silicon condenser microphone diaphragm has been designed that exhibits good predicted directionality, sensitivity, and reliability. The design was based on the structure of a fly’s ear (Ormia ochracea) that has highly directional hearing through mechanical coupling of the eardrums. The diaphragm that is 1mm × 2mm × 20 microns is intended to be fabricated out of polysilicon through microelectromechanical micromachining. It was designed through the finite-element method in ANSYS in order to build the necessary mode shapes and frequencies into the mechanical behavior of the design. Through postprocessing of the ANSYS data, the diaphragm’s response to an arbitrary sound source, sensitivity, robustness, and Articulation Index - Directivity Index (AI-DI) were predicted. The design should yield a sensitivity as high as 100 mV/Pa, an AI-DI of 4.764 with Directivity Index as high as 6 between 1.5 and 5 kHz. The diaphragm structure was predicted be able to withstand a sound pressure level of 151.74 dB. The sound level that would result in collapse of the capacitive sensor is 129.9 dB.. The equivalent sound level due to the self-noise of the microphone is predicted to be 30.8 dBA.



1995 ◽  
Vol 98 (6) ◽  
pp. 3059-3070 ◽  
Author(s):  
R. N. Miles ◽  
D. Robert ◽  
R. R. Hoy


2013 ◽  
Vol 61 (5) ◽  
pp. 2500-2510 ◽  
Author(s):  
Amir R. Masoumi ◽  
Yazid Yusuf ◽  
Nader Behdad


Author(s):  
Andrew P. Lisiewski ◽  
Haijun Liu ◽  
Miao Yu

Miniature directional microphones are desirable and attractive in many applications including micro air vehicles, hearing aid devices, and anti-sniper systems. To overcome the size constraint, the natural world can serve as a source of inspiration. One striking example is found in the parasitoid fly Ormia Ochracea. Although the interaural distance of the fly ears is only 520μm, it can localize its cricket host with a resolution of as small as 2° [1]. The key to this remarkable directional hearing capability has been linked to a mechanical coupling between the fly’s two eardrums [1–3]. By mimicking the fly-ear design, two-membrane devices have been developed in our previous work [4] which can localize sound in one dimension. This work is intended to develop a three-membrane sound localization sensor, with a coupling beam connected between each of the two adjacent membranes. By utilizing the responses from all three membranes, this device can pinpoint a sound source based on the obtained bearing and elevation angles. A reduced-order model with three degrees of freedom has been developed, and parametric studies have been carried out to study the performance of the system. In experiment, the membrane responses have been detected by using a fiber optic interferometric system. The experimental results have demonstrated an improved directional sensitivity compared with that obtained from a conventional microphone array with uncoupled membranes. This work offers an entirely new approach for sensor design and development practice via the seamless integration of bio-inspired solutions, mechanics modeling, micro-fabrication techniques, and optical detection strategies.



2021 ◽  
Vol 9 ◽  
Author(s):  
Andrew C. Mason

Insects are often small relative to the wavelengths of sounds they need to localize, which presents a fundamental biophysical problem. Understanding novel solutions to this limitation can provide insights for biomimetic technologies. Such an approach has been successful using the fly Ormia ochracea (Diptera: Tachinidae) as a model. O. ochracea is a parasitoid species whose larvae develop as internal parasites within crickets (Gryllidae). In nature, female flies find singing male crickets by phonotaxis, despite severe constraints on directional hearing due to their small size. A physical coupling between the two tympanal membranes allows the flies to obtain information about sound source direction with high accuracy because it generates interaural time-differences (ITD) and interaural level differences (ILD) in tympanal vibrations that are exaggerated relative to the small arrival-time difference at the two ears, that is the only cue available in the sound stimulus. In this study, I demonstrate that pure time-differences in the neural responses to sound stimuli are sufficient for auditory directionality in O. ochracea.



2020 ◽  
Vol 63 (4) ◽  
pp. 1299-1311 ◽  
Author(s):  
Timothy Beechey ◽  
Jörg M. Buchholz ◽  
Gitte Keidser

Objectives This study investigates the hypothesis that hearing aid amplification reduces effort within conversation for both hearing aid wearers and their communication partners. Levels of effort, in the form of speech production modifications, required to maintain successful spoken communication in a range of acoustic environments are compared to earlier reported results measured in unaided conversation conditions. Design Fifteen young adult normal-hearing participants and 15 older adult hearing-impaired participants were tested in pairs. Each pair consisted of one young normal-hearing participant and one older hearing-impaired participant. Hearing-impaired participants received directional hearing aid amplification, according to their audiogram, via a master hearing aid with gain provided according to the NAL-NL2 fitting formula. Pairs of participants were required to take part in naturalistic conversations through the use of a referential communication task. Each pair took part in five conversations, each of 5-min duration. During each conversation, participants were exposed to one of five different realistic acoustic environments presented through highly open headphones. The ordering of acoustic environments across experimental blocks was pseudorandomized. Resulting recordings of conversational speech were analyzed to determine the magnitude of speech modifications, in terms of vocal level and spectrum, produced by normal-hearing talkers as a function of both acoustic environment and the degree of high-frequency average hearing impairment of their conversation partner. Results The magnitude of spectral modifications of speech produced by normal-hearing talkers during conversations with aided hearing-impaired interlocutors was smaller than the speech modifications observed during conversations between the same pairs of participants in the absence of hearing aid amplification. Conclusions The provision of hearing aid amplification reduces the effort required to maintain communication in adverse conditions. This reduction in effort provides benefit to hearing-impaired individuals and also to the conversation partners of hearing-impaired individuals. By considering the impact of amplification on both sides of dyadic conversations, this approach contributes to an increased understanding of the likely impact of hearing impairment on everyday communication.



ICCTP 2009 ◽  
2009 ◽  
Author(s):  
J. Zhou ◽  
F. Sun ◽  
X. Hu ◽  
X. Cheng


2019 ◽  
Vol 13 (3) ◽  
pp. 5334-5346
Author(s):  
M. N. Nguyen ◽  
L. Q. Nguyen ◽  
H. M. Chu ◽  
H. N. Vu

In this paper, we report on a SOI-based comb capacitive-type accelerometer that senses acceleration in two lateral directions. The structure of the accelerometer was designed using a proof mass connected by four folded-beam springs, which are compliant to inertial displacement causing by attached acceleration in the two lateral directions. At the same time, the folded-beam springs enabled to suppress cross-talk causing by mechanical coupling from parasitic vibration modes. The differential capacitor sense structure was employed to eliminate common mode effects. The design of gap between comb fingers was also analyzed to find an optimally sensing comb electrode structure. The design of the accelerometer was carried out using the finite element analysis. The fabrication of the device was based on SOI-micromachining. The characteristics of the accelerometer have been investigated by a fully differential capacitive bridge interface using a sub-fF switched-capacitor integrator circuit. The sensitivities of the accelerometer in the two lateral directions were determined to be 6 and 5.5 fF/g, respectively. The cross-axis sensitivities of the accelerometer were less than 5%, which shows that the accelerometer can be used for measuring precisely acceleration in the two lateral directions. The accelerometer operates linearly in the range of investigated acceleration from 0 to 4g. The proposed accelerometer is expected for low-g applications.



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