Patent classifications
H04M9/087
Communication device with echo suppression
The application relates to a communication device, e.g. a speakerphone, comprising a microphone signal path, MSP, and a loudspeaker signal path, SSP, the microphone signal path comprising a microphone unit, an MSP-filter, and a transmitter unit operationally connected to each other and configured to transmit a processed signal originating from an input sound picked up by the microphone, the loudspeaker signal path comprising a receiver unit, an SSP-filter, and a loudspeaker unit operationally connected to each other and configured to provide an acoustic sound signal originating from a signal received by the receiver unit. The communication device comprises a control unit for dynamically controlling the filtering characteristics of the MSP and SSP-filters based on one or more control input signals. This has the advantage of providing a simple and flexible scheme for decreasing echo in a communication device, while ensuring an acceptable sound quality in the transmitted signal.
Receive-path signal gain operations
Operations related to performing gain operations with respect to a receive-path signal of a first device may be performed. The operations may include obtaining the receive-path signal, which includes an echo speech signal and a receive speech signal originating at a second device. In addition, the operations may include identifying a portion of the receive-path signal that includes, at a particular time, a first frequency component that corresponds to the echo speech signal and a second frequency component that corresponds to the receive speech signal in which the first frequency component is different from the second frequency component. Moreover, the operations may include attenuating the first frequency component of the portion while avoiding attenuating the second frequency component of the portion based on the first frequency component corresponding to the echo speech signal and the second frequency component corresponding to the receive speech signal.
RECEIVE-PATH SIGNAL GAIN OPERATIONS
Operations related to performing gain operations with respect to a receive-path signal of a first device may be performed. The operations may include obtaining the receive-path signal, which includes an echo speech signal and a receive speech signal originating at a second device. In addition, the operations may include identifying a portion of the receive-path signal that includes, at a particular time, a first frequency component that corresponds to the echo speech signal and a second frequency component that corresponds to the receive speech signal in which the first frequency component is different from the second frequency component. Moreover, the operations may include attenuating the first frequency component of the portion while avoiding attenuating the second frequency component of the portion based on the first frequency component corresponding to the echo speech signal and the second frequency component corresponding to the receive speech signal.
Echo canceller device and voice telecommunications device
Disclosed is an echo canceller including: a false echo calculator that calculates false echo signals by performing a filtering operation using each of current and previous filter-coefficient groups which used by an adaptive filtering unit on a sequence of reception signals (x(n)); an evaluation value calculator that calculates evaluated values of an echo cancellation quantity on the basis of a voice-transmission signal (y(n)) and the false echo signals; a false echo selector that selects an estimated echo component from the false echo components on the basis of the evaluated values of the echo cancellation quantity; and a signal output unit (S.sub.out) that outputs a residual signal (e(n)).
ECHO CANCELLER DEVICE AND VOICE TELECOMMUNICATIONS DEVICE
Disclosed is an echo canceller including: a false echo calculator that calculates false echo signals by performing a filtering operation using each of current and previous filter-coefficient groups which used by an adaptive filtering unit on a sequence of reception signals (x(n)); an evaluation value calculator that calculates evaluated values of an echo cancellation quantity on the basis of a voice-transmission signal (y(n)) and the false echo signals; a false echo selector that selects an estimated echo component from the false echo components on the basis of the evaluated values of the echo cancellation quantity; and a signal output unit (S.sub.out) that outputs a residual signal (e(n)).
JOINT FAR-END AND NEAR-END SPEECH INTELLIGIBILITY ENHANCEMENT
The invention relates to a computer implemented method for generation of a speech intelligibility enhancement algorithm for a wireless two-way communication system to enhance speech intelligibility in noise at both a near-end and a far-end taking into account joint near-end and far-end noise and audio inputs at the far-end from multiple microphones to capture speech and noise. First, determining (D_SI_OT) a speech intelligibility optimization target, taking into account noise at the near-end and noise at the far-end. Next, determining (D_MVDR) a Minimum Variance Distortionless Response (MVDR) beamformer with a plurality of inputs by optimizing a cost function according to the speech intelligibility optimization target to determine a global optimum. Next, determining (D_FB_G) a set of frequency band dependent gains by optimizing a cost function according to the speech intelligibility optimization target to determine a global optimum of a concave optimization formulation. Finally, generating (G_SIE_A) the speech enhancement processing algorithm as a linear processor with the determined MVDR beamformer followed by the determined set of frequency band dependent gains. In this way, a simple technical-mathematical formulation has been achieved, and the resulting speech intelligibility enhancement is similar to related but complex prior art solutions. The resulting algorithm is suited for wireless two-way communication devices, such as intercom devices to be used in noisy environments. e.g. for firefighters, rescue personnel etc.