Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Other

Mistubishi Electric Corporation

Satoru Furuta

Shinya Takahashi

Hirohisa Tasaki

Tomoharu Awano

Tadashi Yamaura

Jun Ishii

Atsuyoshi Yano

Kosuke Hosoya

Takashi Sudo

Akihiro Ito

Masaru Kimura

Nobuaki Tanaka

Bunkei Matsuoka

Takahiro Otsuka

Yoshinari Yoshida

Keigo Kawashima

Masaru Nishioka

Jin Hirano

Nobuaki Sugiu

Ikuma Nishiguchi

A noise suppression device transforms observation signals to spectral components of multiple channels, calculates an arrival time difference, calculates weight coefficients based on the arrival time difference, estimates whether each of the spectral components of the plurality of frames is a spectral component of target sound or not, estimates a weighted S/N ratio of each of the spectral components of the plurality of frames based on the result of the estimation and the weight coefficients, calculates gains of the spectral components of the plurality of frames by using the weighted S/N ratios, outputs spectral components of an output signal by suppressing spectral components of observation signals of sounds other than the target sound in the spectral components of the plurality of frames by using the gains, and transforms the spectral components of the output signal to an output signal in a time domain.

Noise suppression device, noise suppression method, and storage medium storing noise suppression program

An information processing device includes a signal acquisition unit that acquires a voice signal of an object person outputted from a mic array and a control unit that acquires at least one of noise level information indicating a noise level of noise and first information as information indicating whether or not an obstructor is speaking while obstructing speech of the object person and changes a beam width as a width of a beam corresponding to an angular range of acquired sound, centering at the beam representing a direction in which voice of the object person is inputted to the mic array, and dead zone formation intensity as a degree of suppressing at least one of the noise and voice of the obstructor inputted to the mic array based on at least one of the noise level information and the first information.

Information processing device and control method

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

A sound signal control device in a device including an input transducer to detect sound in a space in a vehicle, a sensor to image an occupant in the space, and an output transducer to emit sound into the space includes: a controller to generate information indicating a position of a head of the occupant and information indicating a state of the occupant, based on an image imaged by the sensor; a processor to generate a cancellation signal for cancelling noise at the position based on a sound signal representing sound detected by the input transducer and the information, and generate a control signal for controlling sound at the position based on the cancellation signal; and a converter to cause the output transducer to emit a sound corresponding to the control signal. The processor adjusts a degree to which the noise is cancelled, based on the information indicating the state.

Sound signal control device and method, and recording medium

A falsification prevention structure is to prevent falsification of the performance of a turbocharger. A bearing housing of the turbocharger has a flow rate adjustment screw which is operated to adjust a turbine flow rate of the turbocharger. The falsification prevention structure includes a cover member which is fastened to a flange portion of the bearing housing by a fixing bolt and which covers the flow rate adjustment screw, and a cap which is mounted in an irremovable manner with respect to the cover member and which blocks a bolt hole.

Prevention of performance falsification of a turbocharger

A speech enhancement device includes: a filter to extract, from an input signal, a component in a frequency band including a fundamental frequency of speech, as a first filter signal; a filter to extract, from the input signal, a component in a frequency band including a first formant of speech, as a second filter signal; a filter to extract, from the input signal, a component in a frequency band including a second formant of speech, as a third filter signal; a mixer to mix the first and second filter signals, thereby outputting a first mixed signal; a mixer to mix the first and third filter signals, thereby outputting a second mixed signal; a controller to delay the first mixed signal, thereby generating a first speech signal for a first ear; and a controller to delay the second mixed signal thereby generating a second speech signal for a second ear.

Speech enhancement device, speech enhancement method, and non-transitory computer-readable medium

A first signal weighting processor outputs a weighted signal obtained by performing a weighting on part of an input signal representing a feature of a target signal included in the input signal. A neural network processor outputs an enhancement signal for the target signal by using a coupling coefficient. An inverse filter cancels the weighting on the feature representation of the target signal in the enhancement signal. A second signal weighting processor outputs a weighted signal obtained by performing a weighting on part of a supervisory signal representing a feature of a target signal. An error evaluator output a coupling coefficient to have a value indicating that a learning error between the weighted signal output from the second signal weighting processor and the output signal of the neural network processor is less than or equal to a set value.

Sound signal enhancement device

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 small-signal power acquisition unit defines a threshold for each of a plurality of input signals based on a long-term average of a minimum power of the corresponding input signal, each of the input signals being obtained by a microphone, sets a power value of each input signal that is smaller than the corresponding defined threshold to be a small-signal power of the input signal. A correction amount setting unit obtains each correction amount for correcting the input signals based on the small-signal power of the corresponding input signal. A correction unit corrects each of the input signals based on each of the correction amounts for correcting the input signals.

Sound collecting apparatus, correction method of input signal of sound collecting apparatus, and mobile equipment information system

An input signal analyzer determines a boundary frequency within the limit of a range which does not exceed a first frequency from the mode of an input signal. A spectrum compressor compresses a power spectrum of frequencies in a band higher than the first frequency in a frequency direction. A gain corrector performs a gain correction on the compressed power spectrum. A spectrum synthesizer reflects the power spectrum outputted from the gain corrector in a band determined by both the first frequency and the boundary frequency. A frequency-to-time converter converts both a synthesized power spectrum provided by the spectrum synthesizer and a phase spectrum of the input signal into ones in the time domain, and outputs these spectra.

Voice emphasis device

A sound source generating unitgenerates from a narrowband audio signal not passing through noise suppression a sound source signal including a fine structure of a band to be restored. On the other hand, a noise suppressing unitperforms noise suppression of the narrowband audio signal and a spectral envelope estimating unitestimates an spectral envelope of the band to be restored. A signal synthesizing unitgenerates a pseudo-audio signal by combining the sound source signal and the spectral envelope, and the band-pass filter unitpasses the pseudo-audio signal of the band to be restored, and the signal addition unitgenerates a broadband audio restoration signal by adding the pseudo-audio signal of the band to be restored to the narrowband audio signal.

Audio signal restoration device and audio signal restoration method

A noise suppression device includes an input signal analyzer that analyzes the harmonic structure and periodicity of a plurality of input signals on the basis of power spectra of a plurality of input signals, a power spectrum synthesizer that synthesizes the power spectra of the plurality of input signals to generate a synthesized power spectrum according to the result of the analysis by the input signal analyzer, a noise suppression amount calculator that calculates an amount of noise suppression on the basis of the synthesized power spectrum and an estimated noise spectrum estimated from the input signals, and a power spectrum suppressor that carries out noise suppression on the synthesized power spectrum by using the calculated amount of noise suppression.

Noise suppression device

A candidate voice segment sequence generatorgenerates candidate voice segment sequencesfor an input language information sequenceby using DB voice segmentsin a voice segment database. An output voice segment sequence determinatorcalculates a degree of match between the input language information sequenceand each of the candidate voice segment sequencesby using a parametershowing a value according to a cooccurrence criterionfor cooccurrence between the input language information sequenceand a sound parameter showing the attribute of each of a plurality of candidate voice segments in each of the candidate voice segment sequences, and determines an output voice segment sequenceon the basis of the degree of match.

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Tokyo, Japan

Satoru Furuta