A quantitative theory of the middle-ear acoustics i developed and expressed interms of an electric analog. The analog network is based on the functional anatomy of the middle ear. The numerical values of its elements are derived from impedance measurements on normal and pathological ears and from anatomical data. It is shown that the input impedance of the analog agrees within the experimental ...

This paper reports the initial results of a test series to evaluate a method for determining the normal incidence impedance of a locally reacting acoustically absorbing liner, located on the lower wall of a duct in a grazing incidence, multi-modal, nonprogressive acoustic wave environment without ow. This initial evaluation is accomplished by testing the methods' ability to converge to the know...

Acoustic impedance mismatch at the fluid-wall interface was shown to affect the spectra from an intravascular Doppler device in an in vitro model with a diameter typical of human coronary arteries. Measurements were obtained first under Poiseuille flow conditions with impedance mismatches of 0%, 7% and 12%, and then under stenosed conditions for the 0% and 7% mismatch cases. For the zero mismat...

Chemotactic responses of Dictyostelium discoideum cells to periodic self-generated signals of extracellular cAMP comprise a large number of intricate morphological changes on different length scales. Here, we scrutinized chemotaxis of single Dictyostelium discoideum cells under conditions of starvation using a variety of optical, electrical and acoustic methods. Amebas were seeded on gold elect...

Some active impedance control experiments in an anechoic chamber are reported. Further active methods are developed for the design of locally controlled absorption liners in air, whose basic principles were described by Olson and May and subsequently investigated practically by Guicking and his colleagues at the beginning of the 80’s. Two methods are described and tested. In the first, processi...

The study of the acoustical in uence of the upstream (vocal-tract) airway in wind instrument performance has been a growing subject of interest in musical acoustics. In a recent study performed on trombone players, we observed a noticeable increase of the acoustic pressure near the fundamental frequency at the input of the vocal tract relative to the acoustic pressure at the input of the instru...