Abstract: A sound collecting apparatus capable of effectively suppressing sounds other than a target sound is provided. The sound collecting apparatus includes a plurality of microphones. A total number of effective microphone pairs in which a distance between two microphones is smaller than a distance D is larger than a total number of the plurality of microphones. The distance D is represented by D=c/2f, where the frequency of the target sound acquired from each of the plurality of microphones is f and sound velocity is c. When an angle formed by a straight line connecting two microphones configuring an effective microphone pair and a predetermined straight line is ?, the angles ? of all effective microphone pairs acquired from the plurality of microphones are different from each other.

Abstract: In a speech recognition method, a criteria value is determined to determine the length of a silent section included in a processing section, and a processing mode to use is determined in accordance with the criteria value. The criteria value is used to obtain audio information of the processing section. Audio processing is executed on the audio information in the processing section, using the processing mode that has been determined. Speech recognition processing is executed on the audio information in the processing section that has been subjected to audio processing.

Abstract: A terminal is provided that includes a speech acquisition unit that acquires first speech information, and a first speech processor that removes noise contained in the first speech information using a first removal method and outputs the noise-removed speech information as second speech information. The terminal also includes a first speech recognition unit that performs speech recognition on the second speech information and outputs the speech recognition result as first speech recognition result information. The terminal further includes a communication unit that receives a speech recognition result as second speech recognition result information from a server, and a determination unit that makes a selection as to which of the first speech recognition result information and the second speech recognition result information should be outputted.

Abstract: A noise reduction device includes an acoustic characteristic determination unit, a microphone pair selection unit, and a noise reduction unit. The acoustic characteristic determination unit determines, using one of microphone pair signals obtained from a plurality of microphone pairs, whether acoustic characteristics of each of the plurality of microphone pairs satisfy a certain requirement. The microphone pair selection unit selects, from among the plurality of microphone pairs, a target microphone pair whose acoustic characteristics have been determined to satisfy the certain requirement. The noise reduction unit reduces, using a microphone pair signal obtained from the target microphone pair, noise included in an input signal obtained from at least one of microphone signals output from a plurality of microphones.

Abstract: A configuration method for a sound collection system for a meeting using a plurality of terminals, the system obtaining speech from the terminals. The method includes: receiving external sounds from the respective terminals as collected-sound data, the external sounds being collected by the respective terminals; and determining a meeting to which each of the terminals belongs, in accordance with a degree of similarity between the collected-sound data. At least one of the receiving the collected-sound data and the determining the meeting is performed by a processor.

Abstract: A speech recognition method is provided that recognizes speech for causing equipment to operate. The method includes acquiring a speech signal from a microphone disposed in a designated space. The method also includes detecting a spatial sound pressure distribution indicating a distribution of sound pressure in the space, on the basis of the acquired speech signal, and detecting a point sound source in the space on the basis of the detected spatial sound pressure distribution. The method further includes judging to conduct a speech recognition process on the acquired speech signal when the point sound source is detected.

Abstract: A speech recognition method acquires sound information via multiple microphones, detects a sound source interval including sound from the sound information, acquires an estimated direction of speech by conducting direction estimation on a speech interval from among the sound source interval, conducts an adaptation process of using the sound information to estimate filter coefficients, decides a buffer size of the sound information to hold in a buffer, based on sound source interval information, estimated direction information, and adaptation process convergence state information, holds the sound information in the buffer according to the buffer size, conducts a beamforming process using the sound information held in the buffer and the filter coefficients to acquire speech information, and conducts speech recognition on the speech information acquired by the beamforming process.

Abstract: In a speech recognition method, a criteria value is determined to determine the length of a silent section included in a processing section, and a processing mode to use is determined in accordance with the criteria value. The criteria value is used to obtain audio information of the processing section. Audio processing is executed on the audio information in the processing section, using the processing mode that has been determined. Speech recognition processing is executed on the audio information in the processing section that has been subjected to audio processing.

Abstract: A terminal includes a speech acquisition unit that acquires first speech information, a first speech processor that removes noise contained in the first speech information using a first removal method and outputs the noise-removed speech information as second speech information, a first speech recognition unit that performs speech recognition on the second speech information and outputs the speech recognition result as first speech recognition result information, a communication unit that receives a speech recognition result as second speech recognition result information from a server, the speech recognition result being a result obtained by performing speech recognition on third speech information, the third speech information being obtained by removing noise contained in the first speech information using a second removal method that removes a larger amount of noise than the amount of noise removed from the first speech information using the first removal method, and a determination unit that makes a selec

Abstract: An echo cancellation apparatus cancels an echo signal included in a second speech signal including the echo signal of a first speech signal, and includes: a first echo replica generating unit generating a first echo replica by processing the first speech signal through a filter whose characteristic is equalized with a acoustic transfer function of amplified sound; a first echo cancelling unit generating and providing a first echo-cancelled signal by subtracting from the second speech signal the first echo replica generated by the first echo replica generating unit; and a filter updating unit generating a nonlinear-converted echo-cancelled signal by performing nonlinear conversion on the first echo-cancelled signal generated by the first echo cancelling unit, and updating the filter characteristic thereby equalizing the filter characteristic with the acoustic transfer function, using the nonlinear-converted echo-cancelled signal, the first speech signal, and a norm of the first speech signal.

Abstract: A speech recognition method that recognizes speech for causing equipment to operate includes: a speech signal acquiring step of acquiring speech signal from a microphone disposed in a designated space; a spatial sound pressure distribution detecting step of detecting a spatial sound pressure distribution indicating a distribution of sound pressure in the space, on the basis of the acquired speech signal; a point sound source detecting step of detecting a point sound source in the space on the basis of the detected spatial sound pressure distribution; and a speech recognition controlling step of judging to conduct a speech recognition process on the acquired speech signal when the point sound source is detected.

Abstract: A configuration method for a sound collection system for a meeting using a plurality of terminals, the system obtaining speech from the terminals. The method includes: receiving external sounds from the respective terminals as collected-sound data, the external sounds being collected by the respective terminals; and determining a meeting to which each of the terminals belongs, in accordance with a degree of similarity between the collected-sound data. At least one of the receiving the collected-sound data and the determining the meeting is performed by a processor.

Abstract: An echo cancellation apparatus is connectable to a speaker configured to output speaker signals and a microphone configured to receive a sound from the speaker and including a plurality of microphone elements. The echo cancellation apparatus includes: a generating unit configured to generate a plurality of sensitivity signals having different sensitivity patterns which represent directionality of the microphone, based on a plurality of microphone signals obtained from the respective microphone signals; a delay estimating unit configured to determine a shortest delay time as an estimated delay time, the shortest delay time being a shortest one of delay times between the speaker signals and the microphone signals, the delay times being obtained from the respective sensitivity signals; and an echo suppressing unit configured to suppress echoes of the plurality of microphone signals using the estimated delay time.

Abstract: An echo cancellation apparatus cancels an echo signal included in a second speech signal including the echo signal of a first speech signal, and includes: a first echo replica generating unit generating a first echo replica by processing the first speech signal through a filter whose characteristic is equalized with a acoustic transfer function of amplified sound; a first echo cancelling unit generating and providing a first echo-cancelled signal by subtracting from the second speech signal the first echo replica generated by the first echo replica generating unit; and a filter updating unit generating a nonlinear-converted echo-cancelled signal by performing nonlinear conversion on the first echo-cancelled signal generated by the first echo cancelling unit, and updating the filter characteristic thereby equalizing the filter characteristic with the acoustic transfer function, using the nonlinear-converted echo-cancelled signal, the first speech signal, and a norm of the first speech signal.

Abstract: An echo cancellation apparatus is connectable to a speaker configured to output speaker signals and a microphone configured to receive a sound from the speaker and including a plurality of microphone elements. The echo cancellation apparatus includes: a generating unit configured to generate a plurality of sensitivity signals having different sensitivity patterns which represent directionality of the microphone, based on a plurality of microphone signals obtained from the respective microphone signals; a delay estimating unit configured to determine a shortest delay time as an estimated delay time, the shortest delay time being a shortest one of delay times between the speaker signals and the microphone signals, the delay times being obtained from the respective sensitivity signals; and an echo suppressing unit configured to suppress echoes of the plurality of microphone signals using the estimated delay time.

Abstract: A multichannel echo canceller according to the present invention includes an echo cancellation section which receives loudspeaker input signals sp1, sp2 including a second acoustic signal to be respectively inputted to a plurality of loudspeakers 10, 20 provided in a first location and detection signals m1, m2 detected by a plurality of microphones 11, 21 provided in the first location; separates a first acoustic signal and a second acoustic signal, which are included in the detection signals m1, m2, by performing signal processing based on an independent component analysis; cancels as an echo the second acoustic signal, which is included in the detection signals m1, m2, by outputting only the separated first acoustic signal to a plurality of loudspeakers 30, 40 provided in a second location.

Abstract: A multichannel echo canceller according to the present invention includes an echo cancellation section which receives loudspeaker input signals sp1, sp2 including a second acoustic signal to be respectively inputted to a plurality of loudspeakers 10, 20 provided in a first location and detection signals m1, m2 detected by a plurality of microphones 11, 21 provided in the first location; separates a first acoustic signal and a second acoustic signal, which are included in the detection signals m1, m2, by performing signal processing based on an independent component analysis; cancels as an echo the second acoustic signal, which is included in the detection signals m1, m2, by outputting only the separated first acoustic signal to a plurality of loudspeakers 30, 40 provided in a second location.