Abstract: A transceiver in a full duplex communication system includes a transmitting circuit coupled to a channel for transmitting a transmit signal to the channel, a cancellation signal generator coupled to the channel for generating a cancellation signal according to the transmit signal, and an echo cancellation device coupled to the transmitting circuit and the cancellation signal generator for attenuating an echo corresponding to the transmit signal with the cancellation signal.

Abstract: A communication circuit for an Ethernet or other network transceiver includes a first sub-circuit having a first input which receives a composite differential signal including first and second differential signal components, a second input which receives a differential replica transmission signal, and an output which provides a differential receive signal which comprises the composite differential signal minus the differential replica transmission signal. The communication circuit also includes a second sub-circuit which produces first and second single-ended replica transmission signals which together substantially comprise a replica of the first differential signal component of the composite differential signal and a third sub-circuit, which is coupled to the first and second sub-circuits, and which produces the differential replica transmission signal from the first and second single-ended replica transmission signals.

Abstract: An echo prevention circuit includes a filter that receives a first digital signal and outputs second and third digital signals; first and second DA converter that convert the second and third digital signals into first and second analog signals respectively; a circuit to subtract the second analog signal from a signal generated by combining the first analog signal and a third analog signal, a circuit to amplify the signal from the subtracting circuit; an AD converter that converts the amplified signal into a digital signal; a responsive signal acquiring unit to acquire a first response signal from the input of the first DA converter to the output of the AD converter and to acquire a second response signal from the input of the second DA converter to the output of the AD converter; and a unit to set filter coefficients based on the first and second response signals.

Abstract: For diagnostic and trouble-shooting purposes, an audio/voice signal capture mechanism is adapted to be interfaced with a time division multiplexed (TDM) transport path-cascaded echo canceler and compression arrangement for an integrated access device (IAD). The audio/voice signal capture mechanism captures a ‘snapshot’ of the audio/voice signals by storing a prescribed number of seconds of audio/voice path signals transmitted in both directions through the IAD, and time stamping the captured audio/voice signals and associated signaling events of interest. In this way, the invention operates as a ‘virtual’ oscilloscope, as it is able to capture pertinent data for any voice call problem along with an associated time stamp event log.

Abstract: A mobile station (MS) and method for estimating received signal strength of a radio signal from a neighboring cell in a cellular radio telecommunication network. The MS measures the received signal strength of the radio signal over a plurality of frames, and calculates an average received signal strength. During an idle frame, the MS receives a synchronization channel (SCH) signal, and determines a channel estimate for the SCH using a known extended training sequence. The extended training sequence is then modified with the channel estimate, and the modified extended training sequence is subtracted from the received SCH signal to obtain a residual signal. The MS calculates a residual energy of the residual signal, and subtracts the residual energy from the average received signal strength of the radio signal to obtain an estimated received signal strength of the radio signal from the neighboring cell.

Abstract: An echo preventing circuit comprises a filter that is inputted with a first digital signal and outputs a second and a third digital signals; a first DA converter that converts the second digital signal into a first analog signal and outputs the first analog signal; a second DA converter that converts the third digital signal into a second analog signal and outputs the second analog signal; an input/output terminal that outputs the first analog signal or that is inputted with a third analog signal; a subtracting circuit that outputs a fourth analog signal obtained by subtracting the second analog signal from a signal formed by combining the first analog signal and the third analog signal; and an AD converter that converts the fourth analog signal into a fourth digital signal and outputs the fourth digital signal, wherein the filter sets filter coefficients for which the fourth analog signal is a signal formed by removing or attenuating the first analog signal from a signal formed by combining the first analog

Abstract: A method and apparatus for reducing crosstalk in a multi-channel communication system is disclosed. In one embodiment, outgoing signals in a multi-channel environment are manipulated into a transform domain, such as the frequency domain. Thereafter, the signals may be combined and modified based on a weighting variable to create a cancellation signal. Combined processing greatly reduces system complexity and increases processing speed. After processing in the transform domain, the cancellation signal undergoes further processing to return the cancellation signal into the time domain. The cancellation signal may then be combined with received signals to cancel crosstalk or echo. A method and apparatus for crosstalk cancellation in the analog domain and digital domain are also disclosed.

Abstract: In a method for echo suppression or cancellation, a reference voice packet is selected from a plurality of reference voice packets based on at least one encoded voice parameter associated with each of the plurality of reference voice packets and the targeted voice packet. Echo in the targeted packet is suppressed or cancelled based on the selected reference voice packet.

Abstract: A system and method for estimating a channel spectrum. The method includes: (a) receiving an input signal from a channel, where the input signal includes one or more major echoes and zero or more minor echoes introduced by the channel; (b) identifying the one or more major echoes present in the input signal; (c) identifying the minor echoes from a filtered autocorrelation function of the input signal in response to a determination that there is only one major echo; (d) identifying the minor echoes from a filtered power spectrum of the input signal in response to a determination that there is more than one major echo; (e) computing a channel spectrum estimate from the major echoes and minor echoes; where the channel spectrum estimate is usable to remove at least a portion of the one or more major echoes and one or more minor echoes from the input signal.

Abstract: A method and a system for implementing echo cancellation. The method (300, 400) can include, on a first communication device (200), generating an acoustic signal (130) corresponding to an audio signal (110) received from a second communication device. Responsive to receiving a portion of the acoustic signal and detecting it is clipped, filter coefficient adaptation in an echo cancellation system (205) can be neutralized. For example, filter coefficients can be maintained at previous values, a control signal (230) that indicates zero error can be provided to an adaptive algorithm (235) that generates filter coefficients (225), a control signal can be provided that indicates to the adaptive algorithm to halt automatic updating of the filter coefficients that are generated, or a control signal can be provided that indicates to an adaptive filter (245) to halt automatic updating of the filter coefficients that are processed.

Abstract: A duplexer for a communication device having a transmission unit, a reception unit and a shared antenna is disclosed. The duplexer comprises a first signal path between the transmission unit and the reception unit, the first signal path comprises a filter unit filtering the reception signal, the filtering unit provides a filtered signal to the reception unit. The duplexer further comprises a second signal path between the transmission unit and the reception unit. The second signal path comprises a cancellation unit which receives a sample of the transmission signal and produces a compensation signal. The injection of the compensation signal to the first signal path reduces the leakage signal, thereby producing a substantially leakage-free reception signal.

Abstract: A novel and useful mechanism for shutting down very small canceller taps that have little influence on the output of the canceller. Disabling or completely disabling these taps results in a significant reduction in power consumption of the circuit incorporating the canceller. Shutting down very low valued canceller taps also results in reduced least mean square (LMS) noise caused by the jittering of the smaller taps of the canceller. Several methods are provided that determine the number and location of the taps to be shutdown. The mechanism of the invention is operative to shut down canceller taps that are lower than a predetermined threshold. Methods include comparing each individual tap to a threshold, comparing an average of each tap to a threshold, comparing groups of taps to a threshold and comparing an average of groups of taps to a threshold. Taps or groups of taps are smaller than the threshold are shutdown thus reducing the power consumption of the canceller.

Abstract: The present invention proposes a method of providing information of the echo path of a speech connection in a Packet Data Network, said method comprising the steps of requesting delay information by means for triggering echo removal, said delay information being obtained by signaling a non-speech measurement data unit to said Packet Data Network by an echo estimation means, and measuring the delay of the echo of said measurement data unit by said echo estimation means; replying the echo delay of said measurement data unit from said echo estimation means; generating delay information including at least said echo delay of said measurement data unit; and adjusting a shift register being related to an echo removing device by the use of said delay information such that the performance of said echo removing device is optimized in view of its echo removing capability.

Abstract: A method of and apparatus for noise reduction for a transceiver transmitting frames over a transmission medium in a frame-based communications network. A transceiver transmit path and a transceiver receive path is provided. A blocking switch is located in the transceiver transmit path, the blocking switch allowing transmit signal propagation when enabled, while preventing both transmit signal propagation and circuit device noise coupling from the transceiver transmit path to the transceiver receive path when the blocking switch is disabled. The blocking switch is disabled when the transceiver transmit path is not transmitting frames over the frame-based communications network.

Abstract: A transceiver for echo and near-end crosstalk cancellation without a loop timing configuration. The transceiver comprises a receiver, a timing recovery circuit, a same-channel phase interpolator, an echo canceller, a near-channel phase interpolator and a near-end crosstalk (NEXT) canceller. The same-channel phase interpolator and the near-channel phase interpolator receive a phase choosing signal from the timing recovery circuit to determine a specific phase from different phases. The same-channel phase interpolator generates a same-channel phase-modified signal with the specific phase and outputs the phase-modified signal to the echo canceller to cancel an echo in the received signal. The near-channel phase interpolator generates a near-channel phase-modified signal with the specific phase and outputs the near-channel phase-modified signal to the NEXT canceller to cancel a NEXT signal in the received signal.

Abstract: A vehicular communications network is disclosed. The network comprises a communications channel for propagating a signal therealong; a nodal communications system; and a signal coupling system coupled to the communications channel and to the nodal communications system for coupling a signal between the communications channel and the nodal communications system.

Abstract: A system and method for provide a stable gain from an adaptive gain control device in a signal path. An echo canceller is also located in the signal path, and is used to provide performance information regarding losses in the signal. This performance information is fed to the automatic gain control device via a connection. The automatic gain control device thereafter uses the performance information to determine a maximum gain that might be provided based upon losses cause by echo conditions. The gain however is limited in order to provide for a stable system. The performance information includes a loss rate that includes a combination of the echo return loss and the echo return loss enhancement.

Abstract: A system and method facilitating acoustic echo cancellation convergence detection is provided. The invention includes an acoustic echo cancellation convergence detector having a center clipping component, a convergence calculator, a convergence filter and a convergence statistic component. The invention provides for the acoustic echo cancellation convergence detector to provide an output regarding convergence of an adaptive filter based, at least in part, upon a filtered convergence statistic. Optionally, the acoustic echo cancellation convergence detector can provide an output associated with convergence history.

Abstract: Devices, softwares and methods send a warning signal when a periodic signal is present in the audio content of a VoIP connection. In response to the warning signal, an acoustic echo canceller of an IP telephone discontinues its adapting process. A signaling network switch detects when a periodic signal is present in the audio content, and issues a warning signal. A signaling call manager device, when it transmits a tone that has periodicity, it also transmits a warning signal.

Abstract: An echo processor includes an echo suppression amount decider which compares a state of an outgoing input signal to be sent including an echo with a state of an incoming input signal and calculates an echo suppression amount based on the comparison, a time-frequency transformer which transforms the outgoing input signal in the time domain into the frequency domain, thereby generating an amplitude spectrum and a phase spectrum, a noise-spectrum estimator which estimates a noise spectrum from the amplitude spectrum, a mixer which mixes an amount of the noise spectrum based on the echo suppression amount with the amplitude spectrum, and a frequency-time transformer which generates an outgoing output signal including a noise in the time domain on the basis of the amplitude spectrum, with which an amount of the noise spectrum is mixed by the mixer, and the phase spectrum, and outputs the outgoing output signal.

Abstract: A distributed echo cancelling architecture is provided where echo-cancelling functions are performed at locations remote from devices receiving signals with echoes. The echo cancelling functions use a reference signal, which has been corrupted with the echoes at the devices, for echo cancellation. As echo canceller resources are located at a central system and not at each individual device, the echo canceller resources can therefore be shared between the devices.

Abstract: A hybrid circuit within a full-duplex transceiver transmits an outgoing signal outward on a communication channel at the same time it receives an incoming signal arriving via the communication channel, and the outgoing and incoming signals sum to form a combined signal. The hybrid circuit generates both the outgoing signal and a replica of the outgoing signal in response to an input signal, and then subtracts the replica from the combined signal in producing a received signal. The received signal includes a component derived from the incoming signal and a residual echo component having peaks resulting from a phase difference between the outgoing signal and its replica. The transceiver periodically digitizes the received signal to produce a data sequence representing the incoming signal.

Abstract: In a mobile communication system employing code division multiple accesses and having radio logical channels such as control channels and traffic channels, for the purpose of interference cancellation processing which is implemented without a large processing delay even under a call control application, the baseband receiving part of the mobile communication system includes a common control channel demodulator 302 which executes the demodulation processing of a common control channel as to a received baseband reception signal 301, an interference canceller 309 which executes interference cancellation processing for a received multiplexed signal on the basis of the notification information of the control channels, and a synthesis/error correction processor 315 which executes error correction processing, etc. as to user information having undergone the interference cancellation processing and thereafter executes frame formation processing.

Abstract: A circuit for transmitting and receiving communications. The circuit includes a transmit block, a receive block, and an echo canceller, coupled to the transmit block and to the receive block, for determining an echo signal and subtracting it from the received signal, the determination of the echo signal involving a predetermined number N of coefficients calculated at the beginning of each of the communications in an initialization phase. The circuit periodically updates during communication a restricted group of coefficients chosen from among the most significant coefficients. The present invention also relates to an echo cancellation method.

Abstract: This invention describes a statistical adaptive-filter controller for digital acoustic echo control in hands-free telephones for achieving more consistent echo cancellation results (i.e. higher output signal quality) and simpler realizations of AEC units. The improvement using the simple statistical adaptive-filter controller is accomplished by optimizing a joint control of an echo canceller and a postfilter.

Abstract: An echo canceler and method for a communications system include an echo-containing signal input for receiving a signal and an echo-causing signal source for developing an echo-causing signal. A first filter coupled to the echo-containing signal input and the echo-causing signal source filters the echo-containing signal over a predetermined time period using an existing filter coefficient set to provide a first echo-canceled output signal at a first filter output mode. A trial filter is coupled to the echo-containing signal input and the echo-causing signal source for processing the echo-containing signal over a predetermined time period using a trial filter coefficient set to provide a trial echo-cancel output signal at the trial filter output mode.

Abstract: An apparatus and method for echo cancellation is presented. The echo canceller comprises an adaptive filter that tracks the impulse response of the echo path and produces an estimate of the echo. Filter adaptation is controlled by a controller based on the rate of the far-end speech signal, the rate of the near-end signal, an acoustic loss measure, and a double talk hangover indicator. The controller may also comprise a step size adaptation unit for determining the adaptation step size of the adaptive filter. In addition, the controller may comprise a noise replacement unit, which controls replacement of the echo residual signal with comfort noise to ensure echo is completely rejected when only the far-end speaker is talking.

Abstract: A method of calculating echo-canceling (EC) coefficients to be used by an echo cancellation filter in a communication modem, the communication modem having a Fast Fourier Transform (FFT) serial to parallel interface, the method including the steps of transmitting a first signal including a wide-band cyclic sequence, generating an echo signal based on the first signal and a plurality of EC coefficients, receiving a second signal including a wide-band cyclic sequence, subtracting the echo-canceled signal from the second signal to produce an echo-cancelled signal, transforming the echo-cancelled signal via the FFT serial to parallel interface to produce a transformed echo-cancelled signal, and calculating the plurality of EC coefficients based on the transformed echo-cancelled signal.

Abstract: An echo canceling system, method of attenuating echo, and a bit pump and transceiver employing the system and method. The echo canceling system is couplable between a transmit and receive path of the bit pump and receives and attenuates the echo in a receive signal propagating along the receive path. In one embodiment, the echo canceling system includes a slave echo canceling stage that employs a filter coefficient to attenuate the echo. The echo canceling system also includes a separation circuit, coupled to the slave echo canceling stage, that generates data representing a residual echo substantially exclusive of the receive signal. The echo canceling system still further includes a master echo canceling stage, coupled to the separation circuit, that receives the data and modifies the filter coefficient based thereon.

Abstract: A method for improving TCP throughput over lossy communication links without affecting performance over non-lossy links comprises determining lookahead-loss which is the number of lost packets in a given loss-window; using the loss-window and lookahead-loss to detect congestion in the communication links; and controlling transmission under congestion conditions and under normal conditions, wherein the controlling transmission comprises controlling a size of the loss-window by beginning in a slow-start phase; advancing to a congestion avoidance phase when a slow-start threshold is reached; entering a halt growth phase when the first level of packet loss has been recovered; returning to the congestion avoidance phase when a first level of packet recovery occurs; entering a k-recovery phase when a second level of packet loss occurs. The loss window and slow-start threshold are reduced in half and returned to the congestion avoidance phase when the second level of packet loss has been recovered.

Abstract: An adapter for reducing echo and noise in internet telephony for use with personal computers. The device employs analog circuitry to provide signal filters and delay which act together to reduce line induced echo and background noise, thus providing a clear voice communication channel. The device is readily inserted between standard microphones and speakers employed in the personal computer.

Abstract: An echo cancellation system for detecting and canceling echo from a network speech path, comprising a pool of echo locators for detecting pure echo delay and dispersion of time, a pool of echo cancellers, a pool of line watchdogs for detecting presence or absence of echo in the network speech path, and a control system for (i) locating and applying an echo locator from the pool of echo locators to the network speech path for detecting the pure echo delay and dispersion of time of any echo in the network speech path, and thereafter returning the echo locator to the pool of echo locators; (ii) locating and applying an echo canceller from the pool of echo cancellers to the network speech path for canceling the echo using the pure delay and dispersion time, and thereafter returning the echo canceller to the pool of echo cancellers; and (iii) locating and applying a line watchdog from the pool of line watchdogs to the network speech path for detecting said presence or absence of echo, and in the event the presence

Abstract: A method and apparatus for reducing echo feedback in a wireless communication system (10) is accomplished when a receiving communication unit (24) senses a feedback signal, or echo, via an ancillary communication path. The receiving communication unit is a targeted recipient of an original audio signal generated by a transmitting communication unit (22), where the original audio signal (42) is conveyed to the receiving communication unit. Upon detecting the feedback signal and determining that it exceeds a feedback threshold, the receiving communication unit attenuates an audible output of the original signal to reduce echo to the transmitting communication unit. In addition, the receiving communication unit, and/or the transmitting communication unit include echo canceller to further minimize the echo within the digital communication system.

Abstract: An echo cancelling system for cancelling echoes in a communication path includes an echo locator and an echo canceller. The echo locator is coupled to the communication path and locates the positions of echo signals received from the communication path. The echo canceller is also coupled to the communication path and cancels echo signals received therefrom. During echo cancellation, the echo canceller becomes active in regions corresponding to the positions of echo signals in response to the echo locator.

Abstract: In a method of running a processor for high performance operation in a communication network one function of the processor is a calculation using an algorithm. The function can include calculation for each of a plurality channels. In situations, when there is not available processor capacity to perform the calculation function for each channel, the quality of the algorithm is degraded in a controlled manner to decrease the amount of necessary calculations so that more channels can be handled. The quality of the algorithm is degraded by dividing the algorithm into subfunctions and by performing only some of the subfunctions in said situations when momentary calculation peak exist.

Abstract: Interference reduction with a current-mode transversal filter having taps including binary current sources is provided. Each binary current source provides an output current having either of two distinct values, depending on a binary input. The product of a tap coefficient and an interference data signal value is obtained by independently generating the contribution from each interference data bit using a binary current source and providing these contributions to a current summing junction. Binary current sources can be implemented in analog, digital, or mixed-mode circuitry. Echo, near end cross talk, and far end cross talk are examples of interference that can be reduced in this manner. The use of binary current sources provides significant flexibility, especially in connection with multilevel modulation schemes such as pulse amplitude modulation (PAM).

Abstract: A network gateway is configured to facilitate on line and off line bi-directional communication between a number of near end data and telephony devices with far end data termination devices via a hybrid fiber coaxial network and a cable modem termination system. The described network gateway combines a QAM receiver, a transmitter, a DOCSIS MAC, a CPU, a voice and audio processor, an Ethernet MAC, and a USB controller to provide high performance and robust operation. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: A separation circuit, method of determining a residual level of an echo, and an echo canceling system, bit pump and transceiver employing the circuit and method. The echo canceling system employing the separation circuit is couplable between a transmit and receive path of the bit pump and generates an echo canceling signal. In one embodiment, the separation circuit includes a symbol determination circuit that accepts a receive signal, propagating along the receive path, substantially free of an echo and determines a symbol associated with the receive signal. The separation circuit also includes an estimator stage, coupled to the symbol determination circuit, that receives the symbol and provides an estimated receive signal. The separation circuit generates data representing a residual level of the echo as a function of the estimated receive signal and the echo canceling signal.

Abstract: Data is transferred by delaying an audio signal less than fifty milliseconds to produce a shadow signal and combining the shadow signal with the audio signal. The shadow represents the data to be transferred A telephone constructed in accordance with the invention has at least two, separate machine states, each of which includes operating in half duplex mode and two, separate machine states, each of which includes operating in full duplex mode. The state is selected based upon one or more shadows detected at the line input of the telephone.

Abstract: When an edge node whose order is lower than that of a primary switch detects a failure of the primary switch, the edge node requests a secondary switch that the secondary switch serves as a host of the edge node itself. At this time, the secondary switch establishes a connection between the secondary switch and the edge node, generates routing information and label information in a core network which does not comprise the primary switch to give the routing information and the label information to the edge node. The secondary switch performs communication between the edge node and the secondary switch by using the routing information and the label information which are received from the secondary switch.

Abstract: A signalling tone detector for use in a communications network carrying voice traffic incorporating single frequency and dual frequency signalling tones comprises a first output path, a second output path, and a switch arranged to selectively couple an input signal to one or other of the output paths. The detector is used for the selective disablement of an echo canceller in the presence of signalling tones.

Abstract: A filter cell, method of deriving an echo component and an echo canceling system, bit pump and transceiver employing the same. In one embodiment, the filter cell includes a first summing node that receives a first input based on a signal sample that contains an echo component of an echo. The filter cell also includes a second summing node that receives a second input based on the signal sample. The filter cell still further includes a multiplier that employs outputs from the first and second summing nodes and a scaling factor to derive first and second outputs containing a remnant of the echo component.

Abstract: A method and an apparatus for echo cancellation in a digital data transmission system in which system the end of a transmission link to which sound returns as an echo is the far end and the end of the transmission link from which an echo is reflected back is the near end, and in which a speech coding method is used on the echo path at least for a far-end signal transmitted from the far end to the near end, the method comprising the following steps: the echo originating from the near end is estimated with an adaptive linear filter on the basis of the far-end signal, and the echo estimate is subtracted from the near-end signal transmitted from the near end to the far end, whereby the speech-encoded far-end signal is decoded in an echo canceller, and the echo originating from the near end is estimated on the basis of said decoded far-end signal.

Abstract: A technique for echo cancellation that suppresses echo leak through includes generating a synthetic echo signal and a center clipper signal from a reference signal, generating an error signal from a desired signal that has been added to a negative of a synthetically generated echo signal; and generating an improved center clipper signal from the center clipper signal, the reference signal, the error signal, and the echo cancelled signal.

Abstract: An apparatus of a digital echo canceller and method therefor, a designed selector is used values of receiving and input signals to estimate the length of a cable. The response values of an insignificant part of the echo signal can be selected. Multiplication and addition operations are carried out in a response region of a significant part of the echo signal. An estimated echo signal is produced to cancel the echo signal, unnecessary operations and the cost of a hardware can be reduced.

Abstract: An echo canceller and a method of echo cancellation using an NLMS algorithm. The NLMS algorithm alternates adaptation between a slow mode, aggressive mode, and inhibition mode, according to the status of the echo canceller. This implementation requires no correlation information. This implementation is simple and not very time consuming. During initial conversation, the NLMS algorithm is in an aggressive mode to ensure fast convergence. After convergence, the NLMS algorithm switches to a slow mode for lower residual echo return. Whenever an abrupt increase of residual echo caused by either double talk or echo path change is detected, the current adaptive filter coefficients are retained and then updated in the aggressive mode. The decision as to which echo estimation (the response of the retained filter or the response of the aggressively adapted filter) is subtracted from the reference echo for echo cancellation within a short detection delay period is determined according to the Geigel algorithm.

Abstract: An electrical circuit in a communications channel is provided. The electrical circuit includes an active resistive summer. The active resistive summer has a composite signal as an input. The composite signal includes a transmission signal component and a receive signal component. A replica transmission signal is also an input to the active resistive summer. The active resistive summer includes the receive signal component as an output.

Abstract: Method and apparatus for an improved echo canceller provide for faster convergence in echo canceling, which also contribute to better voice quality and provide for an increase in the capacity (number of channels) of a multi-channel voice processing products. Whitening filters are used to flatten the spectrum of the signals that pass through the echo canceller. Higher convergence rate is achieved when flattened signals pass through the echo canceller. A reconstruction filter is used to introduce the spectral envelop back into the outbound signal.

Abstract: 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 characteristic of the prompt signal and the input signal. Processing of the input signal to reduce the likelihood of an ASR response thereto is performed if the result of the comparison satisfies a predetermined criterion.

Abstract: A method and apparatus for reducing echo feedback in a wireless communication system (10) is accomplished when a receiving communication unit (24) senses a feedback signal, or echo, via an ancillary communication path. The receiving communication unit is a targeted recipient of an original audio signal generated by a transmitting communication unit (22), where the original audio signal (42) is conveyed to the receiving communication unit. Upon detecting the feedback signal and determining that it exceeds a feedback threshold, the receiving communication unit attenuates an audible output of the original signal to reduce echo to the transmitting communication unit. In addition, the receiving communication unit, and/or the transmitting communication unit include echo canceller to further minimize the echo within the digital communication system.