Lord Corporation

Applied Acoustic Research, Inc.

Noise Cancellation Technologies, Inc.

New Transducers Limited

Future Technologies, Inc.

Glenn E Warnaka

Mark E Warnaka

Michael J Parrella

Lynn A Poole

John M Zalas

Francis J Driscoll

Jiri Tichy

At improved loudspeaker system for a passenger vehicle such as an automobile is disclosed. The system comprises a transducer capable of being excited by applied electric potential and electronic means that is electrically connected to the transducer to apply electric potential thereto. It is a feature of the present invention that the diaphragm driven by the excited transducer is comprised of the trim panel of the vehicle.

Vehicular loudspeaker system

A panel-like sound absorbing structure comprising an upper surface, a lower surface separated from said upper surface and a side surface connecting said upper surface to said lower surface. In the interior of the structure there are a plurality of quarter wave sound absorbing channels disposed in a planar array between said upper and lower surface, said channels having a first, sound-receiving, end into which sound waves are introduced and an end remote from the sound-receiving end, and means for introducing sound waves into said first end of said quarter wave sound absorbing channels. The distance between said upper surface and lower surface is not greater than about 1&Prime;. Alternatively, the interior of the structure can contain one or more Helmholtz resonator cavities.

Sound absorbing structure

An improved loudspeaker system for a passenger vehicle such as an automobile is disclosed. The system comprises a transducer capable of being excited by applied electric potential and electronic means that is electrically connected to the transducer to apply electric potential thereto. It is a feature of the present invention that the diaphragm driven by the excited transducer is comprised of the headliner of the vehicle.

An assembly for utilization in a loudspeaker system is disclosed. The assembly comprises a substantially flat piezoelectric element capable of being excited by applied electric potential, a diaphragm that is driven by the excited piezoelectric element, said diaphragm having a surface area that is at least 20 times the surface area of the piezoelectric element and at least one motion coupler which is attached to at least a portion of the outer perimeter of the piezoelectric element and on its underside to the diaphragm.

Loudspeaker assembly

The invention consists of an integral transducer for a sound radiating diaphragm which may consist of a piezoelectric material, a substrate or a spacer and electrical connector means for a wire harness or other electrical connection. The substrate is used to enhance the motion of the piezoelectric element by spacing the piezoelectric element from the diaphragm. The substrate is larger in area than the piezoelectric element. The transducer system acts to impart motion to a diaphragm. The transducer comprises a piezoelectric element subject to displacement by applied electric potential that has a top side, an under side and an outer perimeter; a substrate that is joined to the underside of the piezoelectric element, and means to apply electric potential to the piezoelectric element.

Piezoelectric transducers

The present invention relates to a sound separating system for separating signals such as intelligible sound, for example, speech, from unwanted noise, such as random noise, when both the noise and the intelligible speech sound are present in an acoustical field and the intelligible speech sound is provided from a source located within the acoustical field. The system comprises a first and second sensing transducer located within the field which both pick up both the intelligible speech sound and the noise. Each sensing transducer generates a representative output signal. The two sensing transducer are in close proximity to each other and the intelligible sound is correlated at said first and second sensing means relative to the sound's source.

Signal separating system

A system for reducing noise of a noise generator such as a fan located in a housing includes a short duct directing air to the fan housing. An input transducer is located in the duct at a position further removed from the fan than a cancellation noise source which is also located in the duct. An electronic controller with embedded frequencies related to the steady state operation of the fan inputs cancellation signals to the cancellation source. The input transducer also responds to the random noise of the fan to provide control signals to the controller for generating signals for the cancellation source. The input duct can be multi-cellular with respect of the input transducer and the cancellation source.

Active noise control

A conventional voice microphone placed in non-critical spaced relation to a source of intelligible speech sound while exposed to an acoustical field of ambient noise, electrically transmits output signals attenuated under control of a signal processing controller to which a sampled input of noise signals is fed by a reference microphone exposed to the same acoustical noise field as the voice microphone for audio reproduction of the speech sound without background noise by programming of the controller.

Noise reducing system for voice microphones

Acoustical energy is directed into a vessel containing an unknown volume of fluid at a frequency at or near the Helmholtz resonance of the vessel. The signal generated within the vessel is analyzed to compare its phase relationship to an electrical reference input signal. The volume of fluid in the vessel may then be determined from said phase relationship, such as by previous empirical calibration of the vessel.

Phase track system for monitoring fluid material within a container

This invention is directed to a system for the active acoustic attenuation of noise produced in the interior of an enclosure by a source of noise which in one aspect comprises input sensing operable to sense the source noise to be attenuated, cancellor adapted to produce noise 180.degree. out of phase with the source noise and error sensor operable to sense the acoustic summation of the source noise and the noise produced by the cancellor. The input sensor, cancellor and error sensor are each preferably disposed at or immediately adjacent an area of high acoustic pressure within the enclosure. The system further includes a second input sensor disposed adjacent the source of noise, a second cancellor adapted to introduce noise 180.degree. out of phase with the source noise at a location at or immediately adjacent the enclosure wall and second error sensor disposed in the interior of the enclosure. Each set of input sensing means, cancellor and error sensor are adapted to be connected to an electronic controller means operable to process signals from the input sensor, produce outputs to drive the cancellor for the introduction of cancelling sound waves into the enclosure for combination with the source sound waves, and then adjust such outputs based on signals received from the error sensor.

Active attenuation of noise in a closed structure

A structure for absorbing wave energy, particularly acoustic wave energy, which includes a first essentially planar surface against which wave energy is directed and a second essentially planar surface generally parallel to and spaced from the first surface. Wedge-shaped elements of sound-absorbing material are disposed between the planar surfaces. All of the wedge-shaped elements, which may be of triangular cross section or pyramidal, have generally flat base portions which form said first planar surface against which wave energy is directed. The apex portions of the wedge-shaped elements are in substantial abutment with the second planar surface. The invention has utility in anechoic applications; however, in contrast to prior art structures of this type, the apex portions of the sound-absorbing material face away from incident wave energy rather than facing toward it.

Structure for absorbing acoustic and other wave energy

An active attenuator is provided for the attenuation of a relatively broad band of lower frequency vibration such as sound waves from a given source, by the introduction of cancelling vibration having the mirror image amplitude and phase characteritics of the source vibration. The active attenuator herein includes an input sensor for detecting the source vibration, a cancelling speaker for generating cancelling vibration, an error sensor for sensing the combination of source and cancelling vibration, and an electronic controller coupled to the input sensor, cancelling speaker and error sensor. The electronic controller includes an adaptive cancelling filter which employs a deterministic algorithm operable to accommodate the propagation delays of the vibration sensed by the input and error sensors, and produce an output to activate and control the cancelling speaker for the production of cancelling vibration.

Active acoustic attenuator

A plurality of parallel and laterally spaced impermeable walls define an array of side-by-side elongate fluid filled cavities. Adjacent open ends of the cavities provide a sound-receiving or admittance end for the sound waves into the cavities. An acoustically reflective, preferably impermeable, barrier is disposed adjacent the ends of the cavities remote from their sound-receiving end and terminates the cavities. The cavities are uniquely configured to provide an effective geometrical sound absorbing structure while minimizing the structural elements required and, thus, the cost of manufacture.

A plurality of parallel and laterally spaced impermeable walls define an array of side-by-side elongate fluid filled cavities. Adjacent open ends of the cavities provide a sound-receiving or admittance end for the sound waves into the cavities. An acoustically reflective, preferably impermeable, barrier is disposed adjacent the ends of the cavities remote from their sound-receiving end and terminates the cavities. The cavities are uniquely configured to provide an effective geometrical sound-absorbing structure while minimizing the structural elements required and, thus, the cost of manufacture.

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State College, PA, United States of America

Glenn E Warnaka