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7636435 Device and method for processing audio signals and telecommunication set equipped with such a processing device  
This device for processing audio signals for telecommunication equipment comprises automatic gain control means ( 18 ) acting on the level of the received audio signal (Sr) by amplifying and...
7555117 Path change detector for echo cancellation  
A path change is detected by multiplying the energy of a signal on the output of a summation circuit in one channel of a telephone by a constant to produce a product. The product is compared with...
7532717 Echo canceler with automatic gain control of echo cancellation signal  
An echo canceler removes the echo of a receive signal from a transmit signal while also controlling the signal level of the transmit signal. The echo canceler generates signal level data for the...
7480377 Dual adaptive filter apparatus and method  
A method and apparatus for adapting dual filters is disclosed. In one aspect, a method may include transforming a signal, adapting a first adaptive filter based on the transformed signal,...
7305083 Echo canceller  
An echo canceller used in a vocal information exchange system operates in such a circumstance that a sound wave released by a speaker is picked up by a microphone unintentionally and works to...
7260213 Telephone echo canceller  
The invention relates to an echo canceling device and method for an arrangement for transmitting audio signals, in particular uttered speech with an echo filter for canceling echo. The echo filter...
7242762 Monitoring and control of an adaptive filter in a communication system  
A communication system having an echo canceller is disclosed. One embodiment of the echo canceller includes an adaptive filter used to provide an estimate of reflected echo which is removed from...
7212628 Echo cancellation/suppression and double-talk detection in communication paths  
A method of suppressing an echo signal in a communication path such as acoustic coupling between a speaker and a microphone in a telephone device handset includes the steps of monitoring a...
7206561 Radio equipment  
A radio equipment, wherein an attenuator ( 10 ) is inserted between antennas ( 91, 92 ) and a radio module ( 2 ), and output and input sensitivities are raised and lowered simultaneously so as to...
7154867 Echo reduction  
This invention provides a technique to reduce echoes not adequately attenuated by echo cancellers during initial periods of voice communication. Signals transmitted across communication networks...
7130413 Microprocessor-controlled full-duplex speakerphone using automatic gain control  
A near full duplex portable handset speakerphone comprises: a microprocessor; a hands-free receive register connected to the microprocessor; a hands-free transmit register connected to the...
7065207 Controlling attenuation during echo suppression  
An echo canceling system receives and transmits audio signals between a far end and a near end. During single talk, which is when only one end is originating audio, the path back to the originator...
7050576 Double talk, NLP and comfort noise  
A state machine for attenuating the transition into and out of NLP state to reduce voice clipping and to reduce echo leak in a voice over packet signal transmission. The state machine interposes...
7039181 Consolidated voice activity detection and noise estimation  
Methods and apparatus compensating for background noise associated with a transmitted signal. In a first embodiment, an adder combines an echo estimate with the the transmitted signal to form a...
7027591 Integrated noise cancellation and residual echo suppression  
A combined processor, such as might be used in a mobile handset or hands-free communication device, provides residual echo suppression and noise reduction while eliminating the need for explicit...
6978009 Microprocessor-controlled full-duplex speakerphone using automatic gain control  
A near full duplex portable handset speakerphone comprises: a microprocessor; a hands-free receive register connected to the microprocessor; a hands-free transmit register connected to the...
6961422 Gain control method for acoustic echo cancellation and suppression  
A gain control method for reducing or eliminating the undesirable effects of acoustic echo coupling between a speaker and a microphone while providing a full-duplex connection. Weighted normalized...
6947550 Acoustic echo cancellation  
The invention is an echo canceller for reducing the magnitude of an echo occurring in a return channel of a communication device and a method of implementing the same. The echo canceller includes a...
6947553 Communication system for controlling training of echo canceller and line switching system  
A communication system being made up of a two-wire/four-wire hybrid circuit, an echo canceller, and a control device and having functions of forming a plurality of communication paths and changing...
6944290 Echo cancellation through auxiliary-vector filtering  
A digit signal processing system may include a near end and a far end connected by a pair of signal transmission paths. A signal processing may be located at the near end through which signal...
6925177 Echo canceler compensating for amplifier saturation and echo amplification  
An echo canceler having a predictive filter that generates an echo replica signal and an adder that subtracts the echo replica signal from a send input signal also has a receive input amplifier and...
6922403 Acoustic echo control system and double talk control method thereof  
An acoustic echo control system and a double talk control method thereof that eliminate echo signals which are generated in a hand-free communication system. In order to discriminate a double talk...
6901141 Echo canceller  
An adaptive digital filter ( 10 ) is adapted to generate a pseudo echo Se which is produced by imitating a noise, using part of receiving signals Si and to output it. An echo produced through an...
6901143 Voice switching system capable of improving a quality of conversation  
In a voice switch, a received voice signal and a transmitted voice signal are inputted to a receiving side control section, the receiving side control section thereby produces a signal for...
6889066 Network echo suppression in mobile stations  
In one embodiment, a mobile station such as a dual-mode, AMPS and CDMA, handset communicates with an AMPS base station in a wireless communication system. The mobile station includes an acoustic...
6839427 Method and apparatus for echo canceller automatic gain control  
A method and apparatus that performs specific automatic gain control in an echo canceller ( 16 ). The disclosed method and apparatus utilize a low complexity algorithm that performs automatic gain...
6816591 Voice switching system and voice switching method  
There are provided a voice switching system and a voice switching method which are capable of carrying out highly accurate voice detection and performing a switching action properly even in the...
6798881 Noise reduction circuit for telephones  
A system for processing audio signals in two channels, wherein each channel includes a plurality of band pass filters for dividing the signal in each channel into a plurality of bands and a...
6757384 Robust double-talk detection and recovery in a system for echo cancelation  
Echoes caused by discontinuities in a telecommunications transmission lines cause double talk which cause divergence problems with echo cancellers. Divergence problems in echo cancellers cause...
6744884 Speaker-phone system change and double-talk detection  
A speaker-phone that is operable to perform system change detection, double-talk detection and if desired, optimal step-size control. The invention differentiates between system change and...
6744885 ASR talkoff suppressor  
A system and method provide ASR talkoff suppression in a prompt-and collect voice transaction system in which a prompt signal is sent and an input signal is received. A comparison is made of a...
6707912 Method and apparatus for setting a step size for an adaptive filter coefficient of an echo canceller  
The step sizes for tap positions of an adaptive filter ( 124 ) in an echo canceller ( 125 ) for canceling an echo signal are individually selected based upon a profile of the echo environment. A...
6704415 Echo canceler  
An echo canceler makes it possible to adaptably control a power of speech reception voice and to reduce distortion of a voice output from a speaker. The echo canceler has a basic structure includes...
6697486 Echo canceler and operating method  
When an echo attenuation amount ACOM(i) is smaller than a desired echo attenuation amount ACOM, and an echo cancellation amount ACANC(i) is equal to or greater than a echo/noise ratio E/N(i), a...
6636604 Method and device for suppressing echo in a hands free device such as a telephone  
An method and a device for echo suppression in a handsfree apparatus, particularly for a telephone is disclosed. With the aid of a control unit, control signals are generated from the signal of the...
6618479 Echo canceler  
An echo canceler for suppressing an echo of a receive signal contained in a transmit signal directed to a telephone circuit and transferring the transmit signal subjected to echo suppression to the...
6606382 System and method for implementation of an echo canceller  
A system and method for canceling an echo signal. An input waveform is provided to an acoustic processor, and a determination is made whether the input waveform includes information representative...
6594360 Circuit configuration for two-wire/four-wire conversion  
The invention relates to a circuit configuration for two-wire/four-wire conversion. The circuit configuration has a receiver which is coupled on an input side to a digital two-wire reception path...
6590974 Howling controller  
A digital signal processing algorithm to cancel howling in a telephone circuit, the telephone circuit being characterized by a receive path and a transmit path in an effective closed loop...
6574336 Echo suppressor and non-linear processor of echo canceller  
The invention relates to an acoustic echo suppressor and a non-linear processor for an echo canceller in a 4-wire data transmission network. An echo canceller is typically controlled by comparing...
6560332 Methods and apparatus for improving echo suppression in bi-directional communications systems  
In methods and apparatus for echo cancellation, a noise estimate is selectively added to a downlink communications signals to improve the convergence speed and stability of an echo-canceling...
6546099 Arrangement for suppressing an interfering component of an input signal  
In an acoustic echocanceller ( 6 ), an estimate of an echo signal is determined by an adaptive filter ( 10 ) and is subtracted from the input signal by a subtracter ( 14 ). The spectrum estimator (...
6526139 Consolidated noise injection in a voice processing system  
Methods and apparatus for compensating for the background noise modulation caused by the operation of a non-linear processor on an audio signal include a controller that receives operating status...
6507653 Desired voice detection in echo suppression  
A hybrid echo suppresser and associated methods of use provide echo suppression in a bi-directional communications system, while minimizing desired-voice signal disruption. The hybrid echo...
6498850 Multichannel echo canceller with a compander  
A compander circuit ( 20 ) for echo cancellation in telecommunications apparatus with an estimator module ( 21 ) for estimating an echo coupling and a delay of a line echo and a characteristic...
6493448 Process for echo suppression with adaptive fir filters  
A process for suppressing total echoes comprising a plurality of partial echoes in telecommunications (TK) equipment such as terminals, transmission systems, or switching equipment by means of...
6483914 Telephone filter arrangement  
A subscriber's telephone installation comprises a plurality of telephone sets coupled in parallel to a subscriber loop so as to provide a voice facility, and a data modern coupled to the subscriber...
6466666 Method and apparatus for echo estimation and suppression  
A threshold estimation method in a telephony system estimates downlink power R x and uplink power R y . Echo model parameter candidates a i and b i are recursively determined for delayed R x ...
6459790 System and method for selective filter isolation  
In a system including a plurality of telephones coupled to an asymmetric digital subscriber line, a circuit operable to facilitate communication using the asymmetric digital subscriber line...
6445791 System and methods for modem interface  
An interface for coupling a modem port with a transmission line includes a hybrid converter having a variable gain amplifier coupling a transmit path of a first differential polarity and a received...
Matches 1 - 50 out of 124 1 2 3 >