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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 of Enclosures
The Journal of the Acoustical Society of America, 1947Formulas are derived for the acoustical impedance of three types of enclosures, a sphere, a cylinder, and a narrow rectangular box. The solutions are valid throughout the entire range from adiabatic to isothermal conditions.
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A Wide Range Adjustable Acoustic Impedance
The Journal of the Acoustical Society of America, 1944A method for obtaining a wide range of calculable impedance values has been developed. Three telescoping tubes are used, one being acoustically “infinite” in length. This “infinite” tube is used as a convenient, calculable impedance terminating the device.
Willard F. Meeker, Frank H. Slaymaker
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Measurement of Acoustic Impedance
The Journal of the Acoustical Society of America, 1948In this paper a method is described of measuring the acoustic impedance of a sample of material forming one boundary of a shallow cylindrical cavity, by determining the sound pressure produced when a known volume current is injected into the cavity from a high impedance source. The volume current is effectively determined by observing the pressure when
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Effect of the Acoustic Reflex on the Impedance at the Eardrum
Journal of Speech and Hearing Research, 1965Seventeen ears of 12 subjects with normal hearing were tested in both a laboratory and a clinical setting to study impedance changes in normal human ears associated with the acoustic reflex. Compliance and resistance at the eardrum were measured with middle ear muscles relaxed and contracted by means of a contralateral noise stimulus, respectively.
A S, Feldman, J, Zwislocki
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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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Impedance Tympanometry and Acoustic Reflectometry at Myringotomy
Pediatrics, 1991A total of 220 ears undergoing myringotomy and pressure-equalizing tube placement were studied with impedance tympanometry and acoustic reflectometry in a direct comparison for detection of middle-ear effusion. Impedance tympanometry and acoustic reflectometry were equally accurate, detecting the presence or absence of middle-ear effusion in 73% and 72%
T R, Babonis, M R, Weir, P C, Kelly
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Acoustic Impedance Studies of the Normal Ear
Journal of Speech and Hearing Research, 1967Repeated measurements of the acoustic impedance at the eardrum were performed on 33 normal subjects. The data are analyzed from the standpoint of the development of criteria for the compliance and resistance parameters of normal impedance as well as ear canal volume measurements.
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Specific acoustic impedance of enamel and dentine
Archives of Oral Biology, 1968Abstract Specific acoustic impedance (SPI) is a characteristic property of matter like elasticity and density to which it is related. A new method for determining longitudinal wave SPI has been employed on enamel and dentine of bovine incisors. The reflection ratio which is the ratio of the reflected pressure amplitude to that of the incident sound ...
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The Acoustical Impedance of an Infinite Hyperbolic Horn
The Journal of the Acoustical Society of America, 1940In discussing the acoustical properties of horns, it is in general a mathematical necessity to assume plane waves. In the case of a horn in the form of an hyperboloid of one sheet, however, it is possible to avoid this assumption and to obtain an exact solution to the problem.
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