Abstract: An audio signal processing method obtains a plurality of audio signals, determines a type of each audio signal of the plurality of audio signals, sets positions of a plurality of virtual speakers, generates, in a case where an audio signal among the plurality of audio signals is determined to be a first type, a first audio signal by performing localization processing on the audio signal determined to be the first type to localize an acoustic image of the first audio signal at a position of any one virtual speaker of the plurality of virtual speakers, generates, in a case where an audio signal among the plurality of audio signals is determined to be a second type, a second audio signal by performing distributed processing on the audio signal determined to be the second type to distribute and localize an acoustic image of the second audio signal at positions of two or more virtual speakers of the plurality of virtual speakers, generates an addition signal by adding the first audio signal and the second audio si

Abstract: A live data distribution method obtains information on a sound source according to sound generated at the first venue, and information on space reverberation, as distribution data, distributes the distribution data to the second venue, and renders the distribution data and providing sound according to the distribution data at the second venue.

Abstract: A live data distribution method obtains first sound source information according to sound of a first sound source generated at a first location of the first venue and position information of the first sound source, and second sound source information according to a second sound source including an ambient sound generated at a second location of the first venue, as distribution data, distributes the distributed data to the second venue, and renders the distribution data and providing first sound of the first sound source having been performed with localization processing based on the position information of the first sound source, and second sound of the second sound source, at the second venue.

Abstract: A talk deciding system includes a receiving portion which receives far-end side decision information indicating a talking state on a far-end side, an inputting portion which inputs an emitted signal from the far-end side, a speaker which emits the emitted signal being input into the inputting portion, a microphone which picks up a voice on a near-end side and outputs a picked-up signal, and a deciding portion which preliminarily decides a talking state on the near-end side based on the picked-up signal being output from the microphone and the emitted signal being input into the speaker, and generates near-end side decision information indicating a talking state on the near-end side. The deciding portion decides the talking state on the near-end side based on the far-end side decision information being received at the receiving portion and the near-end side decision information.

Abstract: A howling suppression apparatus suppresses a howling caused in an acoustic system including a sound collection device and a sound emission device. An estimation part generates an estimated signal by estimating a feedback sound reaching the sound collection device from the sound emission device. An adjustment part generates an estimated signal by adjusting the estimated signal. A spectrum subtraction part generates an acoustic signal using a result of subtracting a frequency spectrum of the estimated signal from a frequency spectrum of an acoustic signal. A filter part generates an acoustic signal by suppressing a component of a frequency band including a howling frequency F among the acoustic signal. An acoustic signal in which the acoustic signal is amplified by an amplifier is supplied to the sound emission device.

Abstract: In an audio processing apparatus, a signal processor controls a volume of a sound signal provided to a sound emitting device. An adaptive filter determines an adaptive signal so as to minimize a magnitude of an error signal. A subtractor generates the error signal represented by a difference between the adaptive signal and an observation signal generated by a sound receiving device. A magnitude ratio calculator calculates a magnitude ratio of the observation signal relative to the error signal or a magnitude ratio of the adaptive signal relative to the error signal for each frame that is sequentially segmented from the error signal along a time axis. A controller variably controls a gain of the volume of the sound signal according to the magnitude of the error signal and the magnitude ratio.

Abstract: An anti-feedback device includes an anti-feedback filter provided in a closed loop. The anti-feedback device down-samples a signal of specific band selected from an output signal of an adaptive target signal transfer system and a signal of the same band selected from an input signal of the transfer system, and a filtering coefficient of the adaptive filter is updated by use of the down-sampled signals. The filter controller controls a filtering characteristic of the anti-feedback filter so that a peak gain of a frequency of an amplitude characteristic within a specific band of a closed loop determined from the filtering coefficient of the adaptive filter is suppressed. Moreover, the filter controller estimates a gain of the closed loop outside the specific band from the amplitude characteristic in the specific band and controls the amount of suppression of the anti-feedback filter outside the band in accordance with a result of estimation.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: An adaptive howling canceller has a plurality of adaptive filters. A delay adds a time delay of an acoustic feedback path to an electric signal fed from an amplifier of a sound-reinforcement system. Each adaptive filter filters the output signal of the delay with a filter coefficient, which is periodically updated at an update interval. The update interval of each adaptive filter is set to decrease successively from a first one to a last one of the adaptive filters. Adders are arranged in correspondence to the adaptive filters in series between a microphone and the amplifier. Each adder subtracts the output signal of the corresponding adaptive filter from an output signal fed from a preceding adder to thereby provide an output signal to a succeeding adder. The output signal from each adder is inputted into the corresponding adaptive filter.

Abstract: An anti-feedback device includes an anti-feedback filter provided in a closed loop, The anti-feedback device down-samples a signal of specific band selected from an output signal of an adaptive target signal transfer system and a signal of the same band selected from an input signal of the transfer system, and a filtering coefficient of the adaptive filter is updated by use of the down-sampled signals. The filter controller controls a filtering characteristic of the anti-feedback filter so that a peak gain of a frequency of an amplitude characteristic within a specific band of a closed loop determined from the filtering coefficient of the adaptive filter is suppressed. Moreover, the filter controller estimates a gain of the closed loop outside the specific band from the amplitude characteristic in the specific band and controls the amount of suppression of the anti-feedback filter, outside the band in accordance with a result of estimation.

Abstract: In an audio amplification apparatus connected to a microphone and a speaker, an audio amplification circuit amplifies an audio signal and inputs the amplified audio signal to the speaker. A howling canceller has an adaptive filter which is set with a filter coefficient based on the audio signal input to the speaker and a residual signal so as to simulate a feedback transmission path from the speaker to the microphone such that the adaptive filter processes the audio signal to produce a simulation signal. The residual signal is obtained by subtracting the simulation signal from an input audio signal inputted from the microphone and fed to the audio amplification circuit. An internal sound source generates the audio signal and inputs the audio signal to the speaker.

Abstract: A method is designed for emphasizing a howling frequency component of a sound signal observed in an acoustic feedback system during an observation period having a predetermined length.

Abstract: A howling suppression apparatus suppresses a howling caused in an acoustic system including a sound collection device and a sound emission device. An estimation part generates an estimated signal by estimating a feedback sound reaching the sound collection device from the sound emission device. An adjustment part generates an estimated signal by adjusting the estimated signal. A spectrum subtraction part generates an acoustic signal using a result of subtracting a frequency spectrum of the estimated signal from a frequency spectrum of an acoustic signal. A filter part generates an acoustic signal by suppressing a component of a frequency band including a howling frequency F among the acoustic signal. An acoustic signal in which the acoustic signal is amplified by an amplifier is supplied to the sound emission device.

Abstract: In an audio processing apparatus, a signal processor controls a volume of a sound signal provided to a sound emitting device. An adaptive filter determines an adaptive signal so as to minimize a magnitude of an error signal. A subtracter generates the error signal represented by a difference between the adaptive signal and an observation signal generated by a sound receiving device. A magnitude ratio calculator calculates a magnitude ratio of the observation signal relative to the error signal or magnitude ratio of the adaptive signal relative to the error signal for each frame that is sequentially segmented from the error signal along a time axis.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: A talk deciding system includes a receiving portion which receives far-end side decision information indicating a talking state on a far-end side, an inputting portion which inputs an emitted signal from the far-end side, a speaker which emits the emitted signal being input into the inputting portion, a microphone which picks up a voice on a near-end side and outputs a picked-up signal, and a deciding portion which preliminarily decides a talking state on the near-end side based on the picked-up signal being output from the microphone and the emitted signal being input into the speaker, and generates near-end side decision information indicating a talking state on the near-end side. The deciding portion decides the talking state on the near-end side based on the far-end side decision information being received at the receiving portion and the near-end side decision information.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: Stereo sound signals are reproduced directly from loudspeakers (SP(L), SP(R)). By using a sum signal and a difference signal of the stereo sound signals as a reference signal, and according to a cross spectrum calculation of the reference signal with a microphone-collected sound signal, calculation is performed to obtain transfer functions of four sound transfer systems between the loudspeakers (SP(L), SP(R)) and microphones (MC(L), MC(R)). The transfer functions obtained are subjected to inverse Fourier transform to obtain impulse responses, which are set in filter means (40-1 to 40-4) to create echo cancel signals and perform echo canceling. This solves the problem of an indefinite coefficient in the echo cancel technique of a multi-channel sound signal.

Abstract: A howling canceler apparatus is used in a sound amplification system having a sound amplifier which connects with a multiple of speakers and one or more of microphones. In the howling canceler apparatus, a plurality of adaptive filters are provided in correspondence to a plurality of feedback transmission paths which are formed between each of the multiple of the speakers and each of the one or more of the microphones. Each adaptive filter is set with a filter coefficient simulating a transfer function of the corresponding feedback transmission path for processing the output sound signal to generate a simulation signal simulating a feedback sound traveling through the corresponding feedback transmission path. Each adaptive filter is capable of setting its own filter coefficient based on the output sound signal and a residual signal.