Results 211 to 220 of about 21,419 (265)
Some of the next articles are maybe not open access.
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.
openaire +2 more sources
Acoustic impedance of the maternal abdomen
The Journal of the Acoustical Society of America, 1993Contact sensors to monitor fetal heart, breathing, and movement sounds with increased sensitivity and bandwidth are under development. To understand the inherent acoustical properties of the maternal abdomen and its interaction with these sensors, the driving-point impedance Z(jω) was measured in nine women during their last trimester of pregnancy.
G R, Wodicka +3 more
openaire +2 more sources
Acoustic Neuromas and the Acoustic Impedance of the Ear
Journal of Speech and Hearing Disorders, 1973The acoustic impedance at the tympanic membrane was measured at frequencies in the range 100–1000 Hz and found to be abnormal on the affected side in four patients with acoustic neuroma. In all four the resistance was abnormally high at low frequencies on the affected side, and in three the reactance of the affected ear was raised relative to that of ...
openaire +2 more sources
A Method of Measuring Acoustic Impedance
The Journal of the Acoustical Society of America, 1932An apparatus s described whereby acoustic impedances may be measured in terms of a known acoustic impedance and the complex ratios of two electrical potentiometer readings to a third. As a known impedance, there is chosen the reactance of a closed tube of uniform bore which is an eighth wave-length long.
openaire +1 more source
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.
openaire +2 more sources
Acoustic Input Impedance of the Human Ear
Acta Oto-Laryngologica, 1966An objective method of measuring the vibrations of the tympanic membrane by means of an improved capacitive-probe system is described. The device has a dynamic range up to 7500 A over the whole audiofrequency range. A new probe tip was developed, serving for conduction of the modulated H.F. signal as well as for the sound transmission.
H, Fischler +4 more
openaire +2 more sources
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.
openaire +1 more source
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
openaire +1 more source
Tonndorf and acoustic impedance
The Journal of the Acoustical Society of America, 1990Juergen was full of ideas that reflected his excellent understanding of the limits of technology and science. At first many of his ideas seemed impractical, but in my experience, he was usually right on target and got the results or data he was after. I learned many practice things from him in the lab; almost every encounter brought a new point of view
openaire +1 more source
Acoustic Impedance Inversion of VSP data
Proceedings, 2013During the drilling stage, VSP plays an important role in predicting the depth of target strata and the lithologic characteristics of the deep strata ahead of the drill bit. Therefore, using VSP data to predict ahead of the drill bit has become a popular topic.
Jing Wang, Yanpeng Li, Jinling Du
openaire +1 more source