Results 291 to 300 of about 96,792 (346)
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Acoustic Impedance Transformation
Archives of Otolaryngology - Head and Neck Surgery, 1987To the Editor .—I read with interest Dr Goode's 1 commentary on the potential for otosurgery to transform "tin" ears into "gold" ears. The author asserts that our conventional beliefs about the middle ear performing acoustic impedance transformation between the atmosphere and the inner ear may be incorrect.
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Acoustic Impedance from Motional Impedance Diagrams
The Journal of the Acoustical Society of America, 1948When an acoustic load is coupled to an electromagnetic transducer through a length of air column, there is a critical length at which an increment in acoustic load produces a maximum increment in electrical impedance. The method described makes use of this critical coupling to obtain an optimum precision in determining an acoustical impedance.
R. D. Fay, J. E. White
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Acoustic Impedance Study of Peritubal Myoclonus
Acta Oto-Laryngologica, 2002An audible clicking sound coexistent with the contractions of the peritubal muscles is thought to be an isolated form of palatal myoclonus that presents with myoclonal contractions of the soft palate, larynx, pharynx and, sometimes, cervicofacial area.
Yetiser, S., Kazkayasi, M., Civitci, D.
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Acoustic impedance estimation using calibration curve for scanning acoustic impedance microscope
2016 International Conference on Knowledge Creation and Intelligent Computing (KCIC), 2016Ultrasonic has been used since several decades ago. One of ultrasonic application is used in medical field to observe mechanical properties of target, such as speed of sound, density, acoustic impedance, attenuation, etc. Several methods are also available to estimate mechanical property of target.
Agus Indra Gunawan +5 more
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Acoustical impedance measurement.
The Journal of the Acoustical Society of America, 2008Many components of specialty transducers have extremely tight acoustic impedance tolerances and become difficult to measure in a production environment. Comparing the device to the acoustical impedance of a cavity is one method of determining its acoustical impedance. A precise method of determining the acoustical impedance is described.
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Surface acoustic impedance and causality
The Journal of the Acoustical Society of America, 2001Several models that are commonly used to calculate the surface acoustic impedance of porous materials are examined in light of the causality requirement in its nonlocal and its approximate local forms. Strict (nonlocal) causality requires that the imaginary part of the surface acoustic impedance be the Hilbert transform of the real part.
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Active Control of Wall Acoustic Impedance
AIAA Journal, 1999A novel kind of acoustic liner with controllable impedance is proposed. A set of active control systems has been designed for this kind of liner to control the sound absorption coefficient or the impedance of the liner. The control is achieved by adjusting the liner cavity depth and bias flow rate through the perforated plate of the liner.
Hongwu Zhao, Xiaofeng Sun
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Acoustic Impedance Transformation-Reply
Archives of Otolaryngology - Head and Neck Surgery, 1987In Reply .—Dr Kimberley is incorrect when he states that "a mechanical/acoustical system such as the external ear is quite incapable of impedance transformation, at any frequency." One way to model the acoustic function of the external ear is as a small horn whose mouth contacts the low specific impedance air of the external environment (41.5 acoustic ...
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Acoustic impedance matching device
The Journal of the Acoustical Society of America, 1982A impedance matching window for an ultrasound transducer comprises a periodic array of stepped structures. Each stepped structure comprises a plurality of parallel matching strips disposed side-by-side on an active surface of a piezoelectric ceramic.
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Acoustic impedance inducing device
The Journal of the Acoustical Society of America, 1989An acoustical impedance inducing device is created for axial insertion into the longitudinal air column of a wind musical instrument. The device includes a first annular band of first predetermined thickness and a second annular band of approximately twice the thickness of the first band.
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