Multipoint communication apparatus

A multipoint communication apparatus for controlling and outputting a signal by combining a plurality of signals receiving from a plurality of other communication apparatuses, comprising:

• a receiving unit for receiving a plurality of signals containing voice volume elements and noise volume elements from the plurality of other communication apparatuses respectively;
• a noise volume estimating unit for calculating the plurality of noise volume elements in the plurality of received signals respectively;
• a signal-to-noise ratio estimating unit for finding the plurality of signal-to-noise ratios of the plurality of receiving signals in accordance with the estimated noise volume elements respectively;
• a control unit for finding the largest signal-to-noise ratio of the receiving signal in the plurality of signal-to-noise and finding a target noise volume from the largest signal-to-noise ratio of the receiving signal and controlling the plurality of signals to adjust to the target noise volume.
• a combining unit for combining the plurality of controlled signals;
• and
• an output unit for outputting a combined signal.

A multipoint communication apparatus for controlling and outputting a signal by combining a plurality of signals receiving from a plurality of other communication apparatuses, comprising:

• a receiving unit for receiving a plurality of signals containing voice volume elements and noise volume elements from the plurality of other communication apparatuses respectively;
• a noise volume estimating unit for calculating the plurality of noise volume elements in the plurality of received signals respectively;
• a control unit for controlling the plurality of signals to adjust the plurality of noise volume elements of the plurality of signals to a predetermined noise volume respectively;
• a combining unit for combining the plurality of controlled signals;
• and
• an output unit for outputting a combined signal.

A volume control unit comprising:

• a spectrum generating unit for dividing a input signal containing voice volume elements and noise volume elements into a plurality of bands and generating a plurality of input spectra representing a signal level of the each band respectively;
• a noise spectrum estimating unit for finding a plurality of noise spectra representing a noise level of the each band from the signal level of the each band respectively;
• a signal-to-noise ratio estimating unit for finding a plurality of signal-to-noise ratios of the each band from a ratio between the input spectrum and the noise spectrum respectively;
• a gain calculating unit for finding a plurality of gains of the each band from a target gain and the signal-to-noise ratio of the each band respectively;
• and
• a multiplier for finding a plurality of output levels of the each band by multiplying the signal level of the each band with the gain of each band respectively.

A multipoint communication apparatus for controlling and outputting a signal by combining a plurality of signals receiving from a plurality of other communication apparatuses, comprising:

• a receiving unit for receiving a plurality of signals containing voice signal elements and noise signal elements from the plurality of other communication apparatuses, respectively;
• a processor for performing a process of adjusting gains of the plurality of signals comprising the steps of:
• estimating the plurality of noise signal elements in the plurality of received signals, respectively;
• adjusting gains of the plurality of signals passing therethrough so as to equalize the levels of the plurality of noise signal elements outputted from the gain element on the basis of the estimated levels of the noise signal elements
• combining the plurality of signals passed through the gain control unit;
• and
• an output unit for outputting a sound signal on the basis of the a combined signal by the combining unit.