Patents for H04R 27 - Public address systems (2,454)
01/1992
01/15/1992EP0465563A1 Speaker power matching method and apparatus
01/02/1992EP0463472A1 Electronic muting circuit for electroacoustic systems or public address systems
12/1991
12/31/1991US5077801 Foreground music system using current amplification
10/1991
10/23/1991EP0453293A2 Sound field variable apparatus
10/15/1991US5058169 Public address system
09/1991
09/26/1991DE4008808A1 Setting system for spaced loudspeakers - allows individual adjustment of loudspeaker sound levels to obtain required sound centre
09/11/1991CN2084697U Computer automatic warning displayer
08/1991
08/14/1991CN2082936U Small size stereo megaphone
08/14/1991CN1053875A Portable type audio reproducing and loudening apparatus
08/07/1991CN2082499U Controller of automatic switch of audio amplifier
07/1991
07/31/1991EP0439309A2 Apparatus for reproducing and amplifying sound
07/03/1991EP0435300A2 Sound equipment system
06/1991
06/26/1991CN2079840U Multifunctional combined electric megaphone capable of receiving, recording, megaphoning and playing
06/09/1991WO1991009396A1 Loudspeaker and horn therefor
06/04/1991US5020630 Loudspeaker and horn therefor
05/1991
05/02/1991CA2029048A1 Public address system
04/1991
04/18/1991WO1991005445A1 Hand-carried auditory assistance apparatus
04/03/1991CN2074521U Automatic time public address set capable of substituting for electric bell
04/02/1991US5004067 Cinema sound system for unperforated screens
02/1991
02/05/1991US4991219 Sound simulation chamber
01/1991
01/17/1991DE3922185A1 Loudspeaker group for telephone conferences - has group of vertically spaced loudspeakers, each with cover, penetrating radiation region of superimposed loudspeaker
01/09/1991CN2069190U Handcraft shaped radio microphone
12/1990
12/26/1990CN2068301U Portable shouting unit
12/05/1990CN2067054U Microphone without squealing and background noise
10/1990
10/17/1990EP0391933A1 Method and device for generating sound in a space for people.
10/04/1990WO1990011669A1 Speaker power matching method and apparatus
09/1990
09/12/1990EP0386846A1 Electro-acoustic system
09/04/1990US4955059 Transmitting system
08/1990
08/29/1990EP0384637A1 Point of sale audio-visual advertising system
08/28/1990US4953218 Foreground music system using current amplification
08/16/1990CA2010001A1 Point of sale audio-visual advertising system
07/1990
07/11/1990EP0377144A2 Method and device for correcting a distortion of the loudness perception of a reproduced-sound presentation
07/11/1990EP0377142A2 Method and device for correcting a distortion of the loudness perception of a reproduced sound presentation
07/11/1990CN2059288U Multi-functional wireless microphone
05/1990
05/16/1990EP0368355A2 Conference box
04/1990
04/26/1990DE3934672A1 Elektroakustisches verfahren zur darbietung von audiosignalen fuer das richtungsorientierte raeumliche hoeren Electro-acoustic method for presenting audio signals for the direction-oriented spatial hear
03/1990
03/14/1990CN2054605U Microphone type audio amplifier with recording and playing function
02/1990
02/27/1990US4905290 Howling protective apparatus
01/1990
01/31/1990CN2052177U Transistor megaphone with great power
01/23/1990US4896360 Public address amplifier
12/1989
12/27/1989CN1038387A Multidimensional stereophonic sound reproduction system
12/14/1989WO1989012373A1 Multidimensional stereophonic sound reproduction system
11/1989
11/14/1989US4881123 Voice override and amplitude control circuit
09/1989
09/21/1989WO1989008970A1 Induction loop driving amplifiers
07/1989
07/13/1989DE3833200A1 Method and device for calibrating public address systems
06/1989
06/06/1989US4837829 Acoustic sound system for a room
05/1989
05/17/1989CN2037910U Multifunctional microphone
05/16/1989US4831656 Conference microphone for use with hearing impaired amplification system
05/05/1989WO1989003919A1 A device for a meeting-hall
04/1989
04/25/1989US4823908 Directional loudspeaker system
04/12/1989CN2035946U Controller for mixing of eight-channel microphone
04/11/1989US4821329 Audio switch device with timed insertion of substitute signal
03/1989
03/28/1989US4815559 Portable loudspeaker apparatus for use in live performances
02/1989
02/21/1989US4805728 For a musical performer
01/1989
01/11/1989CN2030786U Attracted-disk microphone
01/11/1989CN2030785U Telephone receive and pick-up device with background voice adjustable arrangement
01/04/1989EP0297975A1 Sound pick-up and reproduction device, particularly for audio conferences
12/1988
12/21/1988EP0296092A2 Arrangement for wireless earphones without batteries and electronic circuits, applicable in audio-systems or audio-visual systems of all kinds
11/1988
11/30/1988EP0293205A2 Public address amplifier
10/1988
10/11/1988US4777529 Auditory subliminal programming system
10/06/1988EP0170685A4 Control circuit with plural individual selectable controls.
08/1988
08/31/1988EP0279914A2 Receiving device
08/09/1988US4763360 Passenger entertainment system having direct coupled seat receivers
06/1988
06/14/1988EP0226613A4 Noise supression system.
05/1988
05/10/1988CA1236559A1 Hearing aid apparatus
04/1988
04/20/1988CN86210343U Pulse width modulation megaphone
04/05/1988US4736115 Control circuit with plural individual selectable controls
03/1988
03/23/1988EP0260726A2 Passenger entertainment system having direct coupled seat receivers
02/1988
02/02/1988US4723293 Hearing aid apparatus
02/02/1988US4723292 Voice evacuation system
01/1988
01/21/1988DE3723737A1 Reproduction device for stereophonic signals
10/1987
10/07/1987EP0239914A2 An electronic loudspeaker system having a harmonious sound with multiple adjustable sound levels
09/1987
09/24/1987DE3609165A1 Videoconference room furnishing
09/23/1987CN86208319U Transformer for hi fi transistor public-address amplifier
07/1987
07/01/1987EP0226613A1 Noise supression system.
06/1987
06/10/1987EP0224754A2 Electroacoustic discussion arrangement
02/1987
02/19/1987DE3529561A1 Arrangement for replaying a selected audio information from an audio information block of an audio medium
01/1987
01/21/1987CN86201730U Electron horn with multistage and harmonic sound
01/15/1987WO1987000366A1 Noise supression system
12/1986
12/16/1986US4630305 Automatic gain selector for a noise suppression system
12/16/1986US4630304 Automatic background noise estimator for a noise suppression system
12/16/1986CA1215326A1 Motion picture theater loudspeaker system
12/09/1986US4628529 Noise suppression system
08/1986
08/20/1986EP0191492A2 Computer-controlled electro-acoustic device
08/13/1986CN85200511U Language learning machine for deaf-mutes
07/1986
07/01/1986US4598418 For long distance and humane transporting of livestock
06/1986
06/17/1986US4596041 Participant-identification recording and playback system
06/03/1986US4593404 Method of improving the acoustics of a hall
05/1986
05/06/1986CA1204062A1 Console priority control
04/1986
04/29/1986US4586195 Microphone range finder
03/1986
03/13/1986WO1986001670A1 Directional speaker system
02/1986
02/12/1986EP0170685A1 Control circuit with plural individual selectable controls
02/04/1986US4569076 Motion picture theater loudspeaker system
12/1985
12/03/1985CA1197470A1 Sound actuated microphone system
08/1985
08/15/1985WO1985003582A1 Control circuit with plural individual selectable controls
04/1985
04/23/1985US4513284 Console priority control
01/1985
01/29/1985US4496022 System for interrelating sound transducers or sound sources and their environment
01/23/1985EP0131766A1 Hearing aid
01/08/1985US4493101 Anti-howl back device
01/01/1985US4491699 Communication apparatus for hostile environments
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