Results 151 to 160 of about 45,161 (201)
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Modal decomposition method for acoustic impedance testing in square ducts
The Journal of the Acoustical Society of America, 2006Accurate duct acoustic propagation models are required to predict and reduce aircraft engine noise. These models ultimately rely on measurements of the acoustic impedance to characterize candidate engine nacelle liners. This research effort increases the frequency range of normal-incidence acoustic impedance testing in square ducts by extending the ...
Todd, Schultz +2 more
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Modal decomposition method for high-frequency acoustic impedance testing
The Journal of the Acoustical Society of America, 2005Accurate duct acoustic propagation models are required to characterize and reduce aircraft engine noise. These models ultimately rely on measurements of acoustic impedance for candidate materials used in engine nacelle liners. This paper seeks to increase the frequency range of acoustic impedance testing by extending the standard two-microphone method (
Todd Schultz +2 more
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Akustika, 2021
The paper discusses a simple and low-cost method to design four microphone impedance tube of measuring the acoustic properties of building materials. The acoustic properties of the material are defined by the reflection coefficient, absorption coefficient, and transmission coefficient.
Sourabh Dogra, Arpan Gupta
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The paper discusses a simple and low-cost method to design four microphone impedance tube of measuring the acoustic properties of building materials. The acoustic properties of the material are defined by the reflection coefficient, absorption coefficient, and transmission coefficient.
Sourabh Dogra, Arpan Gupta
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Modal Decomposition Method for Acoustic Impedance Testing in Rectangular Ducts
44th AIAA Aerospace Sciences Meeting and Exhibit, 2006Accurate duct acoustic propagation models are required to characterize and reduce aircraft engine noise. These models ultimately rely on measurements of acoustic impedance for candidate materials used in engine nacelle liners. This paper seeks to increase the frequency range of normal incidence acoustic impedance testing in square ducts by extending ...
Todd Schultz +2 more
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Uncertainty Analysis of the Two-Microphone Method for Acoustical Impedance Testing
8th AIAA/CEAS Aeroacoustics Conference & Exhibit, 2002This paper presents two methods for determining the experimental uncertainty of normal-incidence acoustic impedance measurements using the twomicrophone method (TMM). The first method is an analytical technique that extends standard first-order uncertainty methods to complex variables.
Todd Schultz +3 more
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12th AIAA/CEAS Aeroacoustics Conference (27th AIAA Aeroacoustics Conference), 2006
Accurate duct acoustic propagation models are required to predict and mitigate radiated aircraft engine noise. These models ultimately rely on acoustic impedance measurements to characterize candidate engine nacelle liner materials. This paper compares two different methods for normal incidence acoustic impedance testing: the two-microphone method (TMM)
Todd Schultz +2 more
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Accurate duct acoustic propagation models are required to predict and mitigate radiated aircraft engine noise. These models ultimately rely on acoustic impedance measurements to characterize candidate engine nacelle liner materials. This paper compares two different methods for normal incidence acoustic impedance testing: the two-microphone method (TMM)
Todd Schultz +2 more
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Journal of Engineering Mechanics, 2017
AbstractPrevious work has shown that the acoustic-impedance model does not accurately predict blast wave transmission through plates of 10 different materials in air.
Elijah Courtney +3 more
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AbstractPrevious work has shown that the acoustic-impedance model does not accurately predict blast wave transmission through plates of 10 different materials in air.
Elijah Courtney +3 more
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[Clinical applications of acoustic impedance tests].
Annali di laringologia, otologia, rinologia, faringologia, 1975This manuscript briefly outlines the most important areas of clinical impedance audiometry. The author has emphasized the use of impedance audiometry in differentiating different types of middle ear pathology and utilizing the stapedial reflex in the determination of malingering as well as an overall test of the auditory function of the auditory ...
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The bulk acoustic properties of a porous medium, derived from a single impedance test
The Journal of the Acoustical Society of America, 1999In the majority of engineering applications, porous sound absorbing media may be treated as equivalent fluids, with vibration of the solid skeleton being neglected. Most measurement techniques for the bulk acoustic properties of such media (e.g., complex characteristic impedance and propagation constant) involve tests on large samples of material ...
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[The role of acoustic impedance test in the diagnosis for occupational noise induced deafness].
Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases, 2018Objective: To investigate the characteristics of acoustic impedance test and its diagnostic role for occupational noise induced deafness, in order to provide an objective basis for the differential diagnosis of occupational noise induced deafness. Methods: A retrospective study was conducted to investigate the cases on the diagnosis of occupational ...
H, Chen +5 more
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