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    ECHO CANCELLER WITH REDUCED REQUIREMENT FOR PROCESSING POWER
    13.
    发明专利
    ECHO CANCELLER WITH REDUCED REQUIREMENT FOR PROCESSING POWER 未知

    公开(公告)号：AU2003278623A1

    公开(公告)日：2004-09-30

    申请号：AU2003278623

    申请日：2003-11-11

    Applicant: TANDBERG TELECOM AS

    Inventor： MARTON TRYGVE FREDERIK ,  AARNES INGVAR FLATEN

    IPC: H04M9/08 ,  H04M1/58 ,  H04M1/60 ,  H04B3/20 ,  H04B3/23

    Abstract: An echo canceller processing echo, noise and near end talk in a narrower, but still intelligible, frequency band for reducing required processing power and complexity. In a preferred embodiment of the present invention, an input audio signal of captured sound in an audio communication system is decimated and then divided into a number of sub bands by an analyze filter. Each sub band is processed as in background audio echo cancelling by subtracting the signal with an echo estimate from a model of the acoustic signal in the respective sub band, except from that the signal is also bypassed, adjusted by a filter and subtracted from the processed signal. The resulting signals are then recombined by a synthesize filter and interpolated to the original sampling rate and bandwidth. Finally, the output from the synthesize filter is added to the input audio signal, which has been delayed and adjusted by a filter. The filters are controlled by a control algorithm detecting the presence of near end sound, far end sound and noise, so that the filters, and consequently the high pass filter of the echo canceller, only pass high frequency (above low pass frequencies) when only near end sound is detected.

    17.
    发明专利
    未知

    公开(公告)号：DE60327895D1

    公开(公告)日：2009-07-16

    申请号：DE60327895

    申请日：2003-11-11

    Applicant: TANDBERG TELECOM AS

    Inventor： MARTON TRYGVE FREDERIK ,  AARNES INGVAR FLATEN

    IPC: H04M1/58 ,  H04B3/20 ,  H04B3/23 ,  H04M1/60 ,  H04M9/08

    Abstract: An echo canceller processing echo, noise and near end talk in a narrower, but still intelligible, frequency band for reducing required processing power and complexity. In a preferred embodiment of the present invention, an input audio signal of captured sound in an audio communication system is decimated and then divided into a number of sub bands by an analyze filter. Each sub band is processed as in background audio echo cancelling by subtracting the signal with an echo estimate from a model of the acoustic signal in the respective sub band, except from that the signal is also bypassed, adjusted by a filter and subtracted from the processed signal. The resulting signals are then recombined by a synthesize filter and interpolated to the original sampling rate and bandwidth. Finally, the output from the synthesize filter is added to the input audio signal, which has been delayed and adjusted by a filter. The filters are controlled by a control algorithm detecting the presence of near end sound, far end sound and noise, so that the filters, and consequently the high pass filter of the echo canceller, only pass high frequency (above low pass frequencies) when only near end sound is detected.

    20.
    发明专利
    未知

    公开(公告)号：NO20032062D0

    公开(公告)日：2003-05-08

    申请号：NO20032062

    申请日：2003-05-08

    Applicant: TANDBERG TELECOM AS

    Inventor： JOHANSEN TOM-IVAR ,  MUREN PETTER ,  MARTON TRYGVE FREDERIK

    IPC: H04N7/15 ,  H04R27/00 ,  G01S

    Abstract: An arrangement and a method of localizing active speakers in a video conference includes a localization device that locates at least one microphone relative to the camera, while the at least one microphone in turn localizes the relative positions of audio sources. As the microphones are usually positioned close to the audio source in a video conference, the ratio of the distance between microphones relative to the distance between table microphone and audio source is reduced. Thus, the microphones are able to determine the positions of the audio sources with a higher resolution than if placed close to the camera. When the respective positions of the microphones relative to the camera and the audio source are known, the position of the audio source relative to the camera is then determined by means of geometrical calculations.

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