Abstract: An active attenuation system for a DC motor which yields global vibration reduction of slot or other motor induced tonals at the plate on which the motor is mounted without modifying the construction of the motor. The system comprises one or more vibration sensors, a signal synchronized to the slot rate or other motor induced tonal rate, an electronic adaptive controller and the means to supply the control signal into the motor field and/or armature current.

Abstract: 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.

Abstract: This invention outlines several applications of piezoelectric vibrators to produce quality flat panel speakers in passenger cabin applications. A system consisting of an audio amplifier and transformer is used to drive the piezo speaker. The electronics are packaged so that they fit in small modules that can be attached to a cabin structure to produce a speaker. The invention includes a variety of flat panel speaker designs, including one in which the existing structure is converted into a speaker, and thin membrane and or panels that are fitted with piezoelectric elements. A system consisting of cabin quieting and flat panel speakers is also discussed where the mid and high frequency audio is produced by panel speakers and the low frequency audio is produced from dynamic loudspeakers. The cabin systems discussed in this patent are applicable to automobiles, aircraft, trucks and buses.

Abstract: 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.

Abstract: This invention outlines several applications of piezoelectric vibrators to produce quality flat panel speakers in passenger cabin applications. A system consisting of an audio amplifier and transformer is used to drive the piezo speaker. The electronics are packaged so that they fit in small modules that can be attached to a cabin structure to produce a speaker. The invention includes a variety of flat panel speaker designs, including one in which the existing structure is converted into a speaker, and thin membrane and or panels that are fitted with piezoelectric elements. A system consisting of cabin quieting and flat panel speakers is also discussed where the mid and high frequency audio is produced by panel speakers and the low frequency audio is produced from dynamic loudspeakers. The cabin systems discussed in this patent are applicable to automobiles, aircraft, trucks and buses.

Abstract: The present invention is a method and apparatus for conveying audiovisual information. The invention utilizes a speaker as a visual medium. A sheet of material is secured to the radiating face of a speaker. A visual image is then displayed on the sheet of material. Different techniques can be utilized to display the visual image on the sheet of material. For example, a video image can be projected on to the sheet of material or the sheet of material can contain a fixed image. While the visual image is being displayed on the radiating face of the speaker, audible information is being broadcast over the speaker.

Abstract: A decorative speaker cover is disclosed that transforms any loudspeaker into a work of art. The decorative speaker cover of the invention consists of a sheet of material stretched across and adhered to a support frame. The sheet of material contains an artistic work like a picture, design, custom photograph, print, etc. The invention also includes methods for attaching the decorative speaker covers to a loudspeaker cabinet. The disclosed methods allow speaker covers to be readily changed.

Abstract: An active noise cancellation system includes a series of features for more effective cancellation, greater reliability, and improved stability. A particular feature adapted for headset systems includes locating a residual microphone radially offset from the center of a sound generator to detect a signal more similar to that incident upon the eardrum of the user. In addition, an open back headset design includes perforations on the side of the headset instead of the back, so that the perforations are less susceptible to inadvertent blockage. The system also includes a mechanism for detecting changes in the acoustic characteristics of the environment that may be caused, for example, by pressure exerted upon the earpieces, and that may destabilize the cancellation system. The system automatically responds to such changes, for example, by reducing the gain or the frequency response of the system to preserve stability.

Abstract: The invention relates to an improved adaptive spectral estimator for estimating the spectral components in a signal containing both an information signal, such as speech, and noise. A method and system provide for generating noise estimates and then only updating the noise estimates during pauses in an information signal, when speech or other information is not detected, rather than continuously updating the noise estimates. A noise estimate is calculated for each frequency band and provides for the inclusion of a variable mathematical factor that can be set by the user to produce the best sound quality.

Abstract: A method and apparatus for cancelling acoustic echoes that enhances the hands free operation of audio/video conferencing equipment, wireless and cellular telephones, internet and intranet telephones, etc. is disclosed. The method and apparatus use a constrained and orthogonalized, frequency domain, block, least mean square adaptive filter to generate an estimate of an acoustic echo signal. The estimate of the acoustic echo signal is subtracted from a near end microphone signal to provide an echo reduced communication signal. The echo reduced communication signal is then either transmitted or processed further. The further processing can include non-linear processing using an adaptive speech filter. The method and apparatus include a novel method for updating the coefficients of an adaptive filter.

Abstract: An active headset providing for reduction of external noise over a given frequency range by means of a microphone which generates an external noise representative signal processed and fed to a loudspeaker to produce an external noise cancellation signal spectrum, wherein a bridge amplifier circuit is interposed between the microphone and the loudspeaker and the gain of the bridge amplifier for peak amplitude of the noise cancellation signal is user adjustable without substantially reducing the breadth of the given frequency range over which noise reduction is effective.

Abstract: This invention outlines several applications of piezoelectric vibrators to produce quality flat panel speakers in passenger cabin applications. A system consisting of an audio amplifier and transformer is used to drive the piezo speaker. The electronics are packaged so that they fit in small modules that can be attached to a cabin structure to produce a speaker. The invention includes a variety of flat panel speaker designs, including one in which the existing structure is converted into a speaker, and thin membrane and or panels that are fitted with piezoelectric elements. A system consisting of cabin quieting and flat panel speakers is also discussed where the mid and high frequency audio is produced by panel speakers and the low frequency audio is produced from dynamic loudspeakers. The cabin systems discussed in this patent are applicable to automobiles, aircraft, trucks and buses.

Abstract: A vibration control system includes a processor-based circuit which monitors and controls an analog vibration control circuit. The system include, a sensor to detect the undesirable vibrations and a synchronous pulse generator for determining the fundamental frequency of the vibrations emitted by the source. An actuator produces anti-noise to counter unwanted vibrations. The processor circuit tests the system, monitors system functions, and adjusts various parameters to provide optimal performance.

Abstract: 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.

Abstract: This invention involves the integration of piezoelectric speaker panels and microphones into a personal computer with a sound card to form a novel multi-media computer. In addition noise cancellation electronics and algorithms are also applied to enhance performance of the voice recognition system.

Abstract: An active plus selective headset system for provision of active attenuation of broadband noise as well as speech filtering comprising a headset with reference microphones, residual microphones and speakers on each of a pair of open backed muffs and a controller means.

Abstract: An active vibration control system having at least two input sensors generating first signals representative of a primary vibration field, a plurality of actuators driven by second signals and producing a secondary vibration field, monitoring sensors responsive to both the primary and secondary vibration fields and producing third signals, and a controller having one output waveform generator for each second signal and responsive to the first signals to generate respective second signals so that vibration is reduced in a chosen region excited by both the primary and secondary fields, the controller being adaptive to adjust the waveform generator outputs to maintain the reduced vibration in this region.

Abstract: A system and method for using active algorithmically controlled sensing (1a, 1b) and speaker (2a, 2b) for controlling noise from a distributed noise source (5) within an enclosure (6) with a multiple input, multiple output controller (7).

Abstract: This invention relates to an improved adaptive spectral estimator for estimating the spectral components in a signal containing both an information signal, such as speech and noise. The improvements relate to a noise power estimator and a computationally efficient gain calculation method. The adaptive spectral estimator is particularly suited to implementation using digital signal processing and can be used to provide improved spectral estimates of the information signal. It can be combined with a speech or voice recognition system. A further object of the invention is to provide an accurate method for voice detection.

Abstract: An active muffler noise cancellation system having an active controller, a speaker housing with acoustic compliance spaces, a duct extension in communication with said speaker housing and adapted to conform a dipole radiation pattern into a plane wave which can be measured by a microphone.