Mitsubishi Electric Corporation

Mistubishi Electric Corporation

Tomoharu Awano

Atsuyoshi Yano

Satoru Furuta

Masaru Kimura

Takashi Sudo

Jun Ishii

Shigeaki Suzuki

Takashi Mikami

Tadashi Yamaura

Nobuaki Tanaka

Bunkei Matsuoka

Koji Ibata

Tai Tanaka

Jin Hirano

Atsushi Hotta

A sound collection device performs Fourier transform on a first sound reception signal outputted from a first microphone and outputs a first signal, performs Fourier transform on a second sound reception signal outputted from a second microphone and outputs a second signal, estimates an arrival direction of the voice, calculates a phase of a cross-spectrum of the first signal and the second signal, determines a mask coefficient based on an arrival direction phase table indicating a relationship between the phase and the arrival direction regarding each frequency band, the calculated phase, and the estimated arrival direction, separates a signal from the first signal or the second signal by using the mask coefficient, and performs inverse Fourier transform on the separated signal and outputs a signal of a target voice.

Sound collection device, sound collection method, and storage medium storing sound collection program

An information processing device includes a sound signal acquisition unit that acquires sound signals outputted from a mic array, an analysis unit that analyzes frequencies of the sound signals, an information acquisition unit that acquires predetermined information indicating a steering vector in a first direction as a direction from the mic array to a target sound source, and a calculation unit that calculates a filter for formation in a second direction as a direction different from the first direction based on the frequencies and the information indicating the steering vector in the first direction and calculates a steering vector in the second direction by using an expression indicating a relationship between the calculated filter and the steering vector in the second direction.

Information processing device, and calculation method

An information presentation control device includes: an analyzer to calculate a degree of risk based on information regarding an object located around a vehicle; an occupant monitor to determine whether a driver is aware of approach of the object, based on information obtained by imaging the driver with a camera; an image processor to cause at least one of the displays to perform alerting display, based on the degree of risk; and a sound processor to cause the sound output device to generate, as an alerting sound, a sound whose sound image is controlled so that a virtual sound source is localized at a position of at least one of the at least one display, based on the degree of risk. When the driver is aware of the object, the sound processor stops generation of the alerting sound or decreases a sound volume of the alerting sound.

Information presentation control device, information presentation device, information presentation control method, and non-transitory computer-readable recording medium

A microphone array includes first and second microphones (Ma, Mb) placed on a first axis (f), a third microphone (Mc) placed on a plane (fg) formed by the first axis and a second axis (g) and at a position other than on the first axis, and a fourth microphone (Md) placed on a third axis (h), and at a position other than on the plane formed by the first and the second axes, and a processing circuit generates signals (Cx, Cy, Cz) having bidirectionality in first, second and third mutually perpendicular directions (x, y, z), and an omnidirectional signal (Cw), based on signals (Ba to Bd) obtained by sound collection by means of the first to fourth microphones. It is possible to generate signals having bidirectionality in mutually perpendicular directions, and an omnidirectional signal, without using special microphones, and without excessive restrictions with regard to the placement of the microphones.

Sound collection and playback apparatus, and recording medium

Disclosed is an echo canceller () including: a false echo calculator () that acquires current and previous filter-coefficient groups used by an adaptive filtering unit (), and that calculates plural false echo signals by performing a filtering operation using each of the current and previous filter-coefficient groups on a sequence of reception signals (x(n)); a voice-transmission signal buffer that outputs a previous voice-transmission signal (y(n&#x2212;1)); an evaluation value calculator () that calculates plural evaluated values of an echo cancellation quantity by using the previous voice-transmission signal; a filter selector () that selects a new filter-coefficient group on the basis of the plural evaluated values of the echo cancellation quantity; a foreground filter () that performs a filtering operation using the new filter-coefficient group on the sequence of reception signals (x(n)) to generate an estimated echo component; and a subtractor () that subtracts the estimated echo component from a voice-transmission signal to generate a residual signal (e(n)).

Echo canceller device and voice telecommunications device

Disclosed is an echo canceller including: a false echo calculator that calculates false echo signals by performing a filtering operation using each of current and previous filter-coefficient groups which used by an adaptive filtering unit on a sequence of reception signals (x(n)); an evaluation value calculator that calculates evaluated values of an echo cancellation quantity on the basis of a voice-transmission signal (y(n)) and the false echo signals; a false echo selector that selects an estimated echo component from the false echo components on the basis of the evaluated values of the echo cancellation quantity; and a signal output unit (S) that outputs a residual signal (e(n)).

An echo canceller device includes a band adjuster including a filter for performing band adjustment by applying a gain to a signal in a specific frequency band of an input signal, an adaptive filter for inputting a speech reception signal, updating a filter coefficient, and generating a pseudo echo signal using the updated filter coefficient, a band corrector including a filter for correcting a frequency characteristic of a signal obtained by subtracting the pseudo echo signal from an input signal, to a frequency characteristic of the input signal prior to the band adjustment, and a residual echo suppressor for suppressing an echo component that remains in a signal, by a suppression amount, and the residual echo suppressor sets the suppression amount for a signal in a specific frequency band that has been subjected to the band adjustment.

Echo canceller device and echo cancel method

A variable update step size is determined in proportion to a magnitude ratio or magnitude difference between a first residual signal and a second residual signal. The first residual signal is obtained by using adaptive filter coefficient sequence, where the adaptive filter coefficient sequence has been obtained in previous operations of the adaptive equalizer. The second residual signal is obtained by using a prior update adaptive filter coefficient sequence, where the prior update adaptive filter coefficient sequence is obtained by performing a coefficient update with an arbitrary prior update step size on the adaptive filter coefficient sequence having been obtained in previous operations of the adaptive equalizer.

Adaptive equalizer, acoustic echo canceller device, and active noise control device

An echo cancellation device includes: a full-band echo canceller that generates a pseudo-echo signal; a downsample processor that downsamples a received signal and extracts a low-band component delayed by a delay amount D; a delay controller that delays the low-band component by a delay amount D; a delay controller that delays an output signal of the delay controller by a delay amount D; a low-band echo canceller that generates a pseudo-echo signal delayed by a delay amount D+D; and an upsample processor that upsamples the low-band pseudo-echo signal to generate a full-band pseudo-echo signal delayed by the delay amount 2D+D. The delay controllers control the delay amounts Dand Dsuch that a tap length Lsatisfies a condition of L&#x2267;2D+D=D+D, the tap length Lindicating a response time of the adaptive filter in the full-band echo canceller.

Echo cancellation device

A beam-forming device includes a first target sound blockerand a second target sound blockerthat remove a target signal having a correlation mutually from a first sound signal xand a second sound signal xwhich are converted by first and second microphonesand, a phase synchronizerthat synchronizes the phases of the first sound signal xand the second sound signal xand synthesizes these sound signals by using information acquired when the first target sound blockerremoves the target signal, and a noise learnerthat learns a noise component included in an output signal of the phase synchronizerfrom signals from which the target signal is removed by the first target sound blockerand the second target sound blocker

Beam-forming device

An echo canceler includes a signal-to-echo ratio calculating unitand a residual echo suppressing unit. The signal-to-echo ratio calculating unitcomputes a signal-to-echo ratio SE(n) indicating a ratio of an echo component to a received signal x(n) from a first residual signal and a second residual signal. The first residual signal is obtained using a filter coefficient sequence of an update filter, which is obtained up to the previous operation. The second residual signal is obtained using an updated filter coefficient sequence that undergoes a coefficient update which is performed, using an arbitrary update step size &#x3bc;(n), on the filter coefficient sequence of the update filter, which is obtained up to the previous operation. The residual echo suppressing unitsuppresses the echo component contained in the microphone input signal in accordance with the signal-to-echo ratio the signal-to-echo ratio calculating unitcomputes.

Echo canceler and echo detector

An echo cancelling device splits a low-band signal through LPFs having characteristics which do not cause aliasing during downsampling of downsamplers, and splits a high-band signal through HPFs having characteristics which do not cause aliasing during downsampling of downsamplers. The echo canceling device generates a mid-band signal by subtracting the low-band signal and the high-band signal from a pre-split signal by adder-subtractors, and cancels an echo on a band-by-band basis.

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Tokyo, Japan

Tomoharu Awano