A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

An acoustic door comprises a frame as well as a first panel of gypsum mounted on the frame and having its outer face covered with a sheet of metal and its inner face covered with a layer of lead (Pb) to thereby form a first rigid wall. A second panel of gypsum of different thickness has also its outer face covered with a sheet of metal and its inner face covered with a layer of lead to form a second rigid wall. A strip of flexible material adhesive on both sides thereof is used to mount the seco...

An apparatus and method for measuring high temperatures in a boiler transmits pulses of acoustic waves, from one side wall of the boiler to an opposite side wall thereof. Acoustic noise within the boiler, as well as the transmitted pulses of acoustic waves are received at the opposite side of the boiler. The received signal is digitized and compared to a digitized sample of the pulses during a time period which is more than the maximum transit time for the pulses between the side walls. A point ...

The gyrometer comprises a cavity filled with a fluid in the form of a body of revolution having an axis coinciding with the axis of a rotation to be measured. An excitation transducer and a measuring transducer are disposed on the wall of the cavity in a same cross section and offset at an angle of 90.degree.. The excitation transducer excites a first acoustic resonance mode of the cavity and the measuring transducer measures a second mode of resonance induced by Coriolis forces when the cavity ...

An acoustic transducer loudspeaker for converting variations of electrical energy into corresponding variations of acoustic energy is formed of one piece of foamed polymer material having different densities in different portions thereof. The one piece of foamed polymer material has a periphery portion of one density and a diaphragm portion formed in the center thereof and a resilient diaphragm suspension portion separating the periphery porition from the diaphragm portion and having a flexible ...

A sound attenuating muffler for motor vehicle exhaust systems contains a fibrous glass cartridge with a binder-hardened outer shell surrounding a soft fibrous core through which a gas flow tube extends.

An acoustic transducer with a piezoelectric acoustic oscillator member that has a first surface with a common electrode, and a second surface with a predetermined electrode pattern. In some instances the electrodes are individually connected off of the transducer. In other instances some of the electrodes are connected together in sets. Each set is then connected off of the transducer. The individually connected electrodes are connected to an adjacent pedestal supporting a pad that is adapted to...

A system for monitoring air-water borne noise generated by an aircraft flg over a body of water from within the aircraft includes a sonobuoy having a phase linear array of hydrophones suspended beneath the surface of the water and an electromagnetic radar transponder to permit accurate location of the surface position of the sonobuoy and a plurality of electroacoustic transponders to provide positioning information for the hydrophone array located in spaced relation from the first sonobuoy.

An improved pycnometer in which the sample whose volume to be measured is put in a closed chamber to which an electro-mechanical transducer is coupled. The transducer is excited at a constant frequency. The change in impedance of the transducer is then read as a function of the volume of the sample.

This invention provides an acoustic material having high elastic modulus and large internal loss by subjecting a high-modulus stretched polyethylene containing paraffin wax to plasma treatment. When the acoustic material of the present invention is used for a diaphragm of a speaker, for example, it is possible to suppress the fluctuation of frequency characteristics resulting from split vibration, decrease harmonic distortion and improve transient characteristics.