Patents
Sitemap › H04 - Electric communication technique › H04R - Loudspeakers, microphones, gramophone pick-ups or like acoustic electromechanical transducers; Deaf-aid sets; Public address systems › H04R 3 - Circuits for transducers
Patents for H04R 3 - Circuits for transducers (18,190)
10/1999
10/13/1999EP0948787A1 Improved audio reproduction arrangement and telephone terminal
10/13/1999EP0615387B1 Moving picture encoder
10/07/1999DE19814971A1 Verfahren zur Störbefreiung eines Mikrophonsignals Method for eliminating interference of a microphone signal
10/06/1999EP0948237A2 Method for noise suppression in a microphone signal
09/1999
09/30/1999WO1999049698A1 Method and device for operating a microphone system, especially in a motor vehicle
09/30/1999DE19812697A1 Verfahren und Einrichtung zum Betrieb einer Mikrofonanordnung, insbesondere in einem Kraftfahrzeug Method and apparatus for operating a microphone system, in particular in a motor vehicle
09/28/1999CA2149563C Transmitter-receiver having ear-piece type acoustic transducing part
09/23/1999WO1999047998A1 Apparatus for sound reproduction
09/23/1999WO1999041897A3 Method for improving acoustic noise attenuation in hand-free devices
09/22/1999EP0943225A1 Power supply for microphone
09/22/1999EP0943130A1 Method and device for non-stationary separation of signals of various sources
09/22/1999EP0886990B1 Process and device for transmitting sound
09/22/1999CN1229542A Acoustic heterodyne device and method
09/16/1999WO1999046957A1 Microphone and receiver for automatic accompaniment
09/16/1999DE19818611C1 Frequency range equalization method for microphone array e.g. for hands-free phone device in automobile
09/16/1999DE19742803A1 Modification of a known electronic bass booster with loudspeaker protection, esp. for car radios
09/15/1999EP0941631A1 Architecture for a universal serial bus-based pc speaker controller
09/15/1999EP0682801B1 A noise reduction system and device, and a mobile radio station
09/14/1999US5953434 Headband with audio speakers
09/14/1999US5953432 Line source speaker system
09/14/1999US5953431 Acoustic replay device
09/14/1999US5953408 Telephone including an electromechanical transducer, method of adapting the frequency response of such a transducer and method of coding a melody
09/14/1999CA2129102C Feedback level estimator between loudspeaker and microphone
09/10/1999WO1999045743A1 Radio telecommunication terminal
09/10/1999WO1999045741A2 Directional microphone system
09/10/1999CA2288942A1 Radio telecommunication terminal
09/08/1999EP0941013A1 Radio telecommunication terminal
09/08/1999EP0901726A4 Microphone noise rejection system
09/08/1999CN1228205A Apparatus and methods for harmonic enhancement of electronic audio signals
09/07/1999US5949897 Sound reproduction device with active noise compensation
09/02/1999DE19905826A1 Integrated stereophonic sound amplifier circuit
09/01/1999EP0938830A1 Improved directional microphone audio system
09/01/1999CN1227680A A audio A/D converter using frequency modulation
08/1999
08/26/1999DE19806015A1 Verfahren zur Verbesserung der akustischen Rückhördämpfung in Freisprecheinrichtungen A method for improving the acoustic sidetone suppression in hands-free
08/25/1999CN2335331Y Infrared ray microphone device
08/19/1999WO1999041943A1 Loudspeaker with movable virtual point source
08/19/1999WO1999041898A1 Method for improving acoustic noise attenuation in hand-free devices
08/19/1999WO1999041897A2 Method for improving acoustic noise attenuation in hand-free devices
08/19/1999DE19901835A1 Self-tuning crystal notch filter for removing a signal of predefined frequency from an analogue reception signal in an ultrasonic imaging system
08/19/1999DE19804992C1 Loudspeaker drive circuit
08/18/1999EP0936837A2 Electroacoustic transducer of digital type
08/17/1999US5940520 Power circuit for condenser microphone
08/17/1999US5940518 In a vehicle radio
08/17/1999US5940499 Voice switch used in hands-free communications system
08/17/1999US5940118 System and method for steering directional microphones
08/12/1999WO1999027522A3 Audio processing arrangement with multiple sources
08/12/1999DE19805942C1 Verfahren zur Verbesserung der akustischen Rückhördämpfung in Freisprecheinrichtungen A method for improving the acoustic sidetone suppression in hands-free
08/10/1999US5937074 High back emf, high pressure subwoofer having small volume cabinet, low frequency cutoff and pressure resistant surround
08/10/1999US5937072 Audio crossover circuit
08/10/1999US5937071 Sound field expanding apparatus with improved tone control system
08/10/1999US5937070 Noise cancelling systems
08/10/1999US5937009 Sub-band echo canceller using optimum wavelet packets and cross-band cancellation
08/05/1999WO1999039545A2 Directional microphone assembly for mounting behind a surface
08/05/1999WO1999039497A1 Generating calibration signals for an adaptive beamformer
08/05/1999WO1998056208A3 Cabin communication system
08/04/1999EP0801785A4 Industrial headset
08/03/1999US5933506 Transmitter-receiver having ear-piece type acoustic transducing part
08/03/1999CA2174271C Microphone selection process for use in a multiple microphone voice actuated switching system
08/03/1999CA2050843C Noise eliminating element and electrical circuit having the same
07/1999
07/29/1999WO1999038355A1 Method and arrangement for voice communications
07/27/1999US5930733 Stereophonic image enhancement devices and methods using lookup tables
07/27/1999US5930374 Phase coherent crossover
07/27/1999US5930373 Method and system for enhancing quality of sound signal
07/22/1999WO1999037120A1 Microphone apparatus for producing signals for surround reproduction
07/22/1999WO1999037119A1 Feedback control circuit
07/21/1999EP0929825A1 Two-dimensional array transducer and beamformer
07/21/1999CN2330132Y Combined multifunctional earphone
07/15/1999WO1999035883A1 Thin loudspeaker
07/15/1999WO1999035882A1 Audio signal processors
07/15/1999WO1999035881A1 Loudspeaker device and method for driving the same, and audio signal transmitter/receiver
07/15/1999WO1999022366A3 Improved audio reproduction arrangement and telephone terminal
07/14/1999CN1223036A Echo suppressor and non-linear processor of echo canceller
07/13/1999US5923766 Low frequency audio conversion circuit
07/13/1999US5923576 Parallel recursive digital filters
07/13/1999CA2157418C Beamformer using coefficient restrained adaptive filters for detecting interference signals
07/07/1999CN2328142Y Hi-Fi stereo amplifier
07/06/1999US5920633 Thin-wall multi-concentric cylinder speaker enclosure with audio amplifier tunable to listening room
07/01/1999WO1999033324A1 Digital and analog directional microphone
07/01/1999WO1999033201A1 System and method for factoring a merged wave field into independent components
07/01/1999WO1999033173A1 Method and system for driving speakers with a 90 degree phase shift
06/1999
06/29/1999US5918203 Method and device for determining the tonality of an audio signal
06/29/1999US5917923 Loudspeaker system
06/29/1999US5917922 Method of operating a single loud speaker drive system
06/29/1999US5917921 Noise reducing microphone apparatus
06/24/1999WO1999031932A1 Mechanical acoustic crossover network and transducer therefor
06/17/1999WO1999030534A1 Peak to peak signal detector for audio system
06/17/1999WO1999030414A1 Apparatus and methods for enhancing electronic audio signals
06/17/1999WO1999009787A8 A distributed stereo system
06/17/1999CA2313695A1 Apparatus and methods for enhancing electronic audio signals
06/15/1999CA2157652C Method of operating an ultrasonic piezoelectric transducer and circuit arrangement for performing the method
06/08/1999US5910996 Dual audio program system
06/08/1999US5910994 Method and apparatus for suppressing acoustic feedback in an audio system
06/08/1999US5910990 Apparatus and method for automatic equalization of personal multi-channel audio system
06/08/1999US5910115 Method and apparatus for coherence filtering of ultrasound images
06/03/1999WO1999027754A1 A system for a monolithic directional microphone array and a method of detecting audio signals
06/03/1999WO1999027522A2 Audio processing arrangement with multiple sources
06/02/1999EP0919107A1 High back emf, high pressure subwoofer
06/02/1999EP0919096A1 Method for cancelling multichannel acoustic echo and multichannel acoustic echo canceller
06/02/1999CN2322343Y Microphone capable of circulation recording/playing
06/02/1999CN1218603A Process and device for transmitting sound
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