Abstract: According to an embodiment, a diagnostic apparatus includes a sound-emitting unit, at least one measurement unit, and a processor. The sound-emitting unit includes a plurality of speakers arranged at equal angular intervals on a circumference of a circle, and is configured to emit a first vibration sound to a target by using the speakers. The at least one measurement unit is arranged on a central axis of the circle, and is configured to measure a vibration of the target generated in response to the first vibration sound, or a second vibration sound radiated from the target due to the vibration. The processor is configured to diagnose the target based on an output from the at least one measurement unit.

Abstract: According to one embodiment, a noise reduction system includes a microphone, a loudspeaker, and processing circuitry. The processing circuitry switches an operating mode between a control mode and a path characteristic measurement mode, includes a control filter that generates a control signal that causes the loudspeaker to output a control sound for reducing noise, based on a detection signal obtained by detecting a first sound including the noise with the microphone, measures a path characteristic including an acoustic characteristic between the loudspeaker and the microphone, and generates the control filter by using a measurement result of the path characteristic and a noise feature signal including a feature of the noise.

Abstract: According to one embodiment, a sound absorption device includes: a first plate having a plurality of first holes; a second plate facing the first plate in a first direction; a first frame connecting the first plate and the second plate; and a third plate supported by the first frame so as to vibrate in the first direction within the first frame. A first space is formed in the first frame between the first plate and the third plate. A second space is formed in the first frame between the second plate and the third plate. The third plate includes a first portion and a second portion, the second portion having a higher vibration speed than the first portion.

Abstract: An acoustic control apparatus includes a processor with hardware. The processor calculates a first relational expression between acoustic filter coefficients of acoustic filters to be applied to voice signals containing information of sounds played back by two or more sound sources, based on an amplification magnification in a sound amplification control point with respect to the sounds played back by the two or more sound sources, and on transfer functions between the sound amplification control point and the two or more sound sources. The processor calculates a second relational expression between the acoustic filter coefficients, based on information of a frequency of the voice signals, and on an interval between the two or more sound sources. The processor calculates the acoustic filter coefficients based on the first relational expression and the second relational expression.

Abstract: In general, according to one embodiment, a sound inspection apparatus includes: at least three microphones, a removing unit, and an estimation unit; the removing unit calculates an impulse response based on a sound pressure of a radiation sound collected via reference microphone and a first microphone, calculate an impulse response based on the sound pressure of the radiation sound collected via the reference microphone and a second microphone, and remove a component corresponding to the vibration sound from the calculated impulse response; the intensity calculation unit calculates an intensity of the radiation sound based on the impulse response from which the vibration sound is removed; the estimation unit estimates, based on the calculated intensity, a site where an abnormality in the inspection target object has occurred.

Abstract: According to one embodiment, an inspection apparatus includes a vibration sensor, a microphone, and a processor. The vibration sensor detects a vibration of an inspection target object to which the vibration is excited. The microphone arranged near the inspection target object and collects a radiated sound from the inspection target object. The processor calculates an impulse response between the vibration sensor and the microphone. The processor denoises an unnecessary component from the impulse response. The processor converts the impulse response into a frequency characteristic. The processor calculates acoustic energy between the vibration sensor and the microphone based on the frequency characteristic. The processor determine the presence/absence of an abnormal state of the inspection target object.

Abstract: According to one embodiment, an acoustic diagnostic apparatus includes a speaker, a sound receiving unit, a positioning mechanism, first through third calculation units, and an evaluation unit. The speaker emits a sound wave to a diagnosis target. The sound receiving unit includes two microphones to receive a sound wave from the target. The positioning mechanism positions the sound receiving unit. The first calculation unit calculates impulse responses of the microphones. The second calculation unit calculates, based on the impulse responses, an intensity value on a measurement axis passing through the microphones. The third calculation unit calculates a sound absorption coefficient from the intensity value. The evaluation unit diagnoses the target by evaluating an acoustic characteristic based on a change in the sound absorption coefficient.

Abstract: According to one embodiment, an acoustic diagnostic apparatus includes an acoustic vibration unit, an acoustic vibration signal generation unit, a sound receiving unit, an impulse response calculation unit, an analysis unit, and a diagnostic unit. The vibration unit applies an acoustic vibration to a diagnosis target. The signal generation unit continuously inputs an acoustic vibration signal to the vibration unit. The receiving unit receives an evaluation target sound from the target, and output a sound reception signal. The calculation unit calculates an impulse response based on the sound reception signal. The analysis unit calculates an acoustic characteristic using the impulse response, and analyzes a state of the target. The diagnostic unit diagnoses the state of the target based on an analysis result of the analysis unit.

Abstract: According to an embodiment, a diagnostic apparatus includes a sound-emitting unit, at least one measurement unit, and a processor. The sound-emitting unit includes a plurality of speakers arranged at equal angular intervals on a circumference of a circle, and is configured to emit a first vibration sound to a target by using the speakers. The at least one measurement unit is arranged on a central axis of the circle, and is configured to measure a vibration of the target generated in response to the first vibration sound, or a second vibration sound radiated from the target due to the vibration. The processor is configured to diagnose the target based on an output from the at least one measurement unit.

Abstract: According to one embodiment, a diagnostic method includes changing a position of a mechanical structure to be diagnosed with a drive unit based on an acceleration command, the acceleration command being generated based on a log swept sine (LOGSS) signal, calculating an impulse response based on the acceleration command and measured acceleration of the mechanical structure, the measured acceleration being measured by an accelerometer, analyzing at least one of a linear characteristic and a nonlinear characteristic relating to the mechanical structure based on the impulse response, and diagnosing the mechanical structure based on the at least one of the linear characteristic and the nonlinear characteristic relating to the mechanical structure.

Abstract: An online conversation management apparatus includes a processor. The processor acquires, across a network, reproduction environment information from at least one terminal that reproduces a sound image via a reproduction device. The reproduction environment information is information of a sound reproduction environment of the reproduction device. The processor acquires azimuth information. The azimuth information is information of a localization direction of the sound image with respect to a user of the terminal. The processor performs control for reproducing a sound image of each terminal based on the reproduction environment information and the azimuth information.

Abstract: An acoustic inspection apparatus includes a vibration sound source, a microphone group, and a processor. The vibration sound source emits a vibration sound to an inspection target object. The microphone group includes a first microphone arranged near the inspection target object and a second microphone arranged to have an interval with respect to the first microphone. The processor calculates a first impulse response between the first and second microphones, denoises a component corresponding to the vibration sound from the first impulse response, converts, into a frequency characteristic, a second impulse response obtained from the first impulse response, calculates acoustic energy between the first and second microphones based on the frequency characteristic, and determines an abnormal state of the inspection target object based on the acoustic energy.

Abstract: According to one embodiment, a system for reducing interference noise of rotor and stator blades includes rotor blades, stator blades, loudspeakers, one or more reference microphones, and a controller. The rotor blades rotate about a central axis. The loudspeakers are discretely arranged on a circle that has a center positioned on the central axis. Each loudspeaker generates a control sound. The controller causes the loudspeakers to generate control sounds of a same phase and a same amplitude. The control sounds correspond to the loudspeakers. The r is selected based on a preset attenuation level concerning the interference noise, and the k, where a is a length of the rotor blades, b is a radius of the circle, r=a/b, k is an upper limit wavenumber.

Abstract: An acoustic inspection apparatus includes a vibration sound source, a microphone group, and a processor. The vibration sound source emits a vibration sound to an inspection target object. The microphone group includes a first microphone arranged near the inspection target object and a second microphone arranged to have an interval with respect to the first microphone. The processor calculates a first impulse response between the first and second microphones, denoises a component corresponding to the vibration sound from the first impulse response, converts, into a frequency characteristic, a second impulse response obtained from the first impulse response, calculates acoustic energy between the first and second microphones based on the frequency characteristic, and determines an abnormal state of the inspection target object based on the acoustic energy.

Abstract: According to one embodiment, an acoustic control apparatus includes a first calculator, a second calculator, and a first setting unit. The first calculator calculates a first relationship established between acoustic filter coefficients, based on sounds emitted from sound sources. The second calculator calculates a second relationship established between the acoustic filter coefficients by matching a first sound pressure ratio with a second sound pressure ratio, in a complex sound pressure ratio between ears of a user who desires the sound information. The first setting unit sets an acoustic filter coefficient corresponding to each of the sound sources, based on the first relationship and the second relationship.

Abstract: According to one embodiment, an estimating apparatus includes an insertion tube, a first sensor, a second sensor, a processing unit, an adder, and an analyzer. The insertion tube is detachably mounted midway along a coupling tube that couples an excitation source to a main unit. The first sensor is provided inside the insertion tube at a first distance from an exit of a space housing the excitation source. The second sensor is provided at a second distance from the first sensor. The processing unit performs filter processing to a first signal obtained by the first sensor. The adder adds a filtered signal and a second signal obtained by the second sensor, the first signal being the first signal having undergone filter processing by the processing unit. The analyzer analyzes a frequency of a signal obtained by the adder.

Abstract: Diagnostic device including a hammering sound signal acquisition unit, a frequency characteristic conversion unit, and an abnormality determination unit. The hammering sound signal acquisition unit acquires an i-th hammering sound signal and a j-th hammering sound signal representing hammering sounds with respect to striking applied to an i-th and a j-th struck position of an inspection target. The frequency characteristic conversion unit respectively converts the i-th hammering sound signal and the j-th hammering sound signal into an i-th frequency characteristic and a j-th frequency characteristic. The abnormality determination unit determines presence or absence of an abnormality in the inspection target on the basis of a matching degree of waveforms around peaks in the i-th frequency characteristic and waveforms around peaks in the j-th frequency characteristic. The diagnostic device can be used with an inspection robot to automatically analyze for loose stator wedges.

Abstract: According to one embodiment, an acoustic control apparatus includes a first calculator, a second calculator, and a first setting unit. The first calculator calculates a first relationship established between acoustic filter coefficients, based on sounds emitted from sound sources. The second calculator calculates a second relationship established between the acoustic filter coefficients by matching a first sound pressure ratio with a second sound pressure ratio, in a complex sound pressure ratio between ears of a user who desires the sound information. The first setting unit sets an acoustic filter coefficient corresponding to each of the sound sources, based on the first relationship and the second relationship.

Abstract: According to one embodiment, a noise reduction device includes speakers, microphones, and a processing circuit. The speakers are arranged around a rotor and emit control sound based on control signals. The microphones are arranged around the rotor and convert the control sound and noise emitted by the rotor into microphone signals. The processing circuit generates the control signals for reducing acoustic power in positions of the microphones, based on the microphone signals, rotation speed of the rotor, and a phase of noise that reaches the microphones from the rotor.

Abstract: A sound generating device according to an embodiment includes a sound tube and a sound generator. The sound tube is to be held between a tragus and an antitragus. The sound generator is disposed inside the sound tube.