A conference terminal and a feedback suppression method are provided. In the method, a transmitting sound signal is divided into sub sound signals of multiple frequency bands. Different sub sound signals correspond to different frequency bands. An interfered frequency band corresponding to the howling interference is detected according to the sub sound signals of those frequency bands. The power of the sub sound signal of the interfered frequency band increases along with time. The interfered frequency band is affected by the howling interference. An interference direction is determined according to multiple input sound signals received by the microphone array and merely pass through the interfered frequency band. A sound from the interference direction leads to the howling interference. A beam pattern of the microphone array is determined according to the interference direction. The gain of the beam pattern in the interference direction is reduced.

An embodiment for cancelling echo in online conference systems is provided. According to some embodiments of the present disclosure, the computer-implemented method comprises, in response to an update of devices of participants in an online conference, dividing, by one or more processors, the devices in an online conference into a plurality of groups, wherein the devices located in a same physical location are divided into a same group. The method also comprises, in response to an update of the devices in an online conference, selecting at least one speaker of the devices in each of the plurality of groups as a representative speaker for each of the plurality of groups. The method further comprises forwarding audio data received from microphones of the devices in one of the plurality of groups to the respective representative speaker of other groups of the plurality of groups.

Systems and methods are described to enable a device of a user to automatically join an ongoing conference, where the device is not currently joined to the conference. A first audio signature is generated based on voices of users already in the conference, and a second audio signature is generated based on an audio signal captured by a microphone of the device associated with the first user when the device associated with the first user was not joined to the conference. The first audio signature and the second audio signature are compared, and in response to determining that first audio signature matches the second audio signature, the device associated with the first user is joined to the conference.

Method and System for avoiding howling disturbance especially on conferences, wherein the method comprising the steps of using a howling detector unit implemented inside a multipoint control unit to receive an audio stream input from a client, analyzing the audio input with the howling detector in order to verify if howling noise is present, using at least two of a skewness analysis, a flatness analysis, a crest analysis, a rolloff analysis and preventing the audio stream input to be forwarded as an output to an audio mixer, if howling noise is present.

A system includes participant nodes that unicast a voice stream to a master node and receive a multicast voice stream from the master node. The multicast voice stream may be a mixed voice stream mixing the voice streams of the participants. In this case, each participant performs echo cancellation on the multicast voice stream. Alternatively, the multicast voice stream may be a multiplexed voice stream multiplexing the voice streams of all participants. In this case, each participant de-multiplexes the multicast voice stream and generates a mixed voice stream that does not include that participant. Alternatively, the multicast voice stream received by each participant may be a multiplexed digital voice stream multiplexing multiple mixed streams including one mixed stream that does not include the voice stream of that participant. In this case, each participant de-multiplexes the multicast voice stream to obtain the mixed stream that does not include that participant.

A conference terminal and a feedback suppression method are provided. In the method, a transmitting sound signal is divided into sub sound signals of multiple frequency bands. Different sub sound signals correspond to different frequency bands. An interfered frequency band corresponding to the howling interference is detected according to the sub sound signals of those frequency bands. The power of the sub sound signal of the interfered frequency band increases along with time. The interfered frequency band is affected by the howling interference. An interference direction is determined according to multiple input sound signals received by the microphone array and merely pass through the interfered frequency band. A sound from the interference direction leads to the howling interference. A beam pattern of the microphone array is determined according to the interference direction. The gain of the beam pattern in the interference direction is reduced.

An embodiment for cancelling echo in online conference systems is provided. According to some embodiments of the present disclosure, the computer-implemented method comprises, in response to an update of devices of participants in an online conference, dividing, by one or more processors, the devices in an online conference into a plurality of groups, wherein the devices located in a same physical location are divided into a same group. The method also comprises, in response to an update of the devices in an online conference, selecting at least one speaker of the devices in each of the plurality of groups as a representative speaker for each of the plurality of groups. The method further comprises forwarding audio data received from microphones of the devices in one of the plurality of groups to the respective representative speaker of other groups of the plurality of groups.

A method for initialization of a group of customer premises equipment devices (CPEs) during a training that registers capabilities of the CPEs is disclosed, wherein at least one CPE registers late to the training and cannot be registered. The method includes determining capabilities of the CPEs during a joining phase of the training, wherein it is determined whether a CPE device is capable of employing vectoring and placing in a hold status the at least one CPE that registers late by keeping a line active that is coupled to the at least one CPE. The method further includes providing another joining phase after the joining phase to register the at least one CPE that registers late.

The present invention relates to a sound effect control method and apparatus, where the method includes: when a hands-free call is performed for a mobile terminal, detecting whether a hands-free call channel of the mobile terminal is shielded; and adjusting a configuration of the hands-free call channel of the mobile terminal and/or outputting an alarm signal to inform a user that the hands-free call channel is shielded, when it is detected that the hands-free call channel of the mobile terminal is shielded. According to the method, when a hands-free call is performed for a mobile terminal, whether a hands-free call channel of the mobile terminal is shielded is detected; when it is shielded, a configuration of the hands-free call channel of the mobile terminal is adjusted and/or an alarm signal is output, which can effectively improve quality of the hands-free call of the mobile terminal.

An echo removal device comprises: an echo canceller that includes a first delay unit configured to delay a reception signal from a communication counterpart, and that is configured to subtract, from a transmission signal for the communication counterpart, a cancellation signal that is generated based on the delayed reception signal obtained by the first delay unit and property information which simulates a property of an echo path; a second delay unit configured to delay the reception signal by an amount of delay different from an amount of delay of the first delay unit; an echo suppressor configured to receive the delayed reception signal obtained by the second delay unit and an output of the echo canceller; and a delay amount calculator configured to calculate and set the amount of delay of the first delay unit and the amount of delay of the second delay unit based on the property information.