Abstract: A first filter coefficient and a second filter coefficient are calculated by using spatial transfer characteristics from a first speaker and a second speaker to a first control point and a second control point, and a first sound increase ratio na at the first control point and a second sound increase ratio nb at the second control point, so that, when the first filter coefficient is a through characteristic, a first composite sound pressure from the first speaker and the second speaker to the first control point is na times a first sound pressure from the first speaker to the first control point, and a second composite sound pressure from the first speaker and the second speaker to the second control point is nb times a second sound pressure from the first speaker to the second control point.

Abstract: According to one embodiment, an acoustic control apparatus includes an acquisition unit, a detection unit, a correction unit, and an output unit. The acquisition unit acquires a first acoustic signal. The detection unit detects an information sound. When the detection unit detects the information sound, the correction unit corrects the first acoustic signal to a second acoustic signal by convoluting the first acoustic signal with a first function. The first function represents an acoustic transfer characteristic from a virtual position to a listening position. The virtual position is located along a first direction from the listening position. The output unit outputs the second acoustic signal.

Abstract: According to an embodiment, a speaker system includes filters, speakers, and a sound collection unit. Each of the filters filters a first signal to generate a second signal. The speakers are arranged so that transfer characteristics from the speakers to an evaluation point are different from each other. Each of the speakers converts the second signal generated by a corresponding one of the filters into a sound wave. The sound collection unit combines sound waves output from the speakers to generate a combined sound wave. The filters are formed so that a transfer characteristic from the first signal to an output signal matches a target transfer characteristic, the output signal indicating a sound pressure of the combined sound wave at the evaluation point.

Abstract: According to an embodiment, a control filter coefficient is calculated in such a manner that a second spatial average of one or more complex sound pressure ratios at one or more target binaural positions when a first loudspeaker and a second loudspeaker emit a second acoustic signal and a first acoustic signal is approximated to a first spatial average of one or more complex sound pressure ratios at the one or more target binaural positions when a target virtual acoustic source emits the first acoustic signal.

Abstract: According to one embodiment, an active noise-reduction apparatus includes following units. The reference signal generation unit generates different reference signals based on target sound generated from a sound source. The filter processing unit generates first control signals by filtering the reference signals using first digital filters. The averaging unit generates a second control signal by averaging the first control signals. The control speaker outputs the second control signal as control sound. The error microphone detects a synthetic sound pressure of the target sound and the control sound to generate an error signal. The filter update unit updates the first digital filters so that the error signal is minimized.

Abstract: A first speaker radiates a first sound toward first and second listening points by a first sound signal. A second speaker radiates a second sound toward these points by a second sound signal. The first sound signal is generated by convolving a signal with a first filter coefficient. The second sound signal is generated by convolving the signal with a second filter coefficient. A nearer speaker to a virtual sound source is decided among the first and second speakers. The first and second filter coefficients are calculated so that a ratio of a first sound pressure of the first and second sounds at the first listening point to a second sound pressure thereof at the second listening point is equal to a target ratio. Among the first and second filter coefficients, based on one filter coefficient corresponding to the nearer speaker, the other filter coefficient corresponding to another speaker is calculated.

Abstract: According to an embodiment, an audio control apparatus includes a calculation unit and a determination unit. The calculation unit is configured to calculate an interaural cross-correlation function of a binaural recording signal at regular time intervals. The determination unit is configured to determine that a signal zone in which peak times of interaural cross-correlation functions are consecutively included in one of a plurality of time ranges determined in advance is a localized-sound zone in which a sound-image is localized, each of the peak times being a time at which a corresponding cross-correlation function takes a maximum value.

Abstract: According to one embodiment, a pressure sensor includes a base, and a first sensor unit. The first sensor unit includes a first transducer thin film, a first strain sensing device and a second strain sensing device. The first strain sensing device includes a first magnetic layer, a second magnetic layer, and a first intermediate layer provided between the first and the second magnetic layers. The second strain sensing device is provided apart from the first strain sensing device on the first membrane surface and provided at a location different from a location of the barycenter, the second strain sensing device including a third magnetic layer, a fourth magnetic layer, and a second intermediate layer provided between the third and the fourth magnetic layers, the first and the second intermediate layers being nonmagnetic. The first and the second strain sensing devices, and the barycenter are in a straight line.

Abstract: According to one embodiment, a pressure sensor includes a base, and a first sensor unit. The first sensor unit includes a first transducer thin film, a first strain sensing device and a second strain sensing device. The first strain sensing device includes a first magnetic layer, a second magnetic layer, and a first intermediate layer provided between the first and the second magnetic layers. The second strain sensing device is provided apart from the first strain sensing device on the first membrane surface and provided at a location different from a location of the barycenter, the second strain sensing device including a third magnetic layer, a fourth magnetic layer, and a second intermediate layer provided between the third and the fourth magnetic layers, the first and the second intermediate layers being nonmagnetic. The first and the second strain sensing devices, and the barycenter are in a straight line.

Abstract: According to one embodiment, a loudspeaker is provided in a case of an earphone. The case closes an external auditory canal extended from a tympanum of a listener. The earphone has an opening toward the external auditory canal. In an apparatus for generating a sound reproduction to the loudspeaker, a storage unit stores a correction filter in which a maximum of a gain at a frequency band lower than or equal to 10 kHz is larger than a maximum of a gain at a frequency band higher than 10 kHz. An acquisition unit acquires a first sound reproduction signal. A correction unit generates a second sound reproduction signal by convoluting the correction filter with the first sound reproduction signal. An output unit outputs the second sound reproduction signal to the loudspeaker.

Abstract: A first filter coefficient and a second filter coefficient are calculated by using spatial transfer characteristics from a first speaker and a second speaker to a first control point and a second control point, and a first sound increase ratio na at the first control point and a second sound increase ratio nb at the second control point, so that, when the first filter coefficient is a through characteristic, a first composite sound pressure from the first speaker and the second speaker to the first control point is na times a first sound pressure from the first speaker to the first control point, and a second composite sound pressure from the first speaker and the second speaker to the second control point is nb times a second sound pressure from the first speaker to the second control point.

Abstract: A first loudspeaker group driven by a first sound reproduction signal, radiates a plurality of first sounds, and generates a first sound image synthesized from the plurality of first sounds. A second loudspeaker group driven by a second sound reproduction signal, radiates a plurality of second sounds, and generates a second sound image synthesized from the plurality of second sounds. The first and second sound reproduction signals are generated so that a first sound pressure ratio of a first control point to a second control point is equal to a second sound pressure ratio of the first control point to the second control point. The first sound pressure ratio is formed by a third sound radiated from a virtual sound source driven by a target sound reproduction signal. The second sound pressure ratio is formed by a third sound image synthesized from the first and second sound images.

Abstract: According to one embodiment, a sound image localization apparatus includes following units. The first signal generating unit is configured to generate a first acoustic signal. The first speaker is configured to generate a first sound according to the first acoustic signal. The input unit is configured to input a localization magnification n. The first control filter unit is configured to adjust the first acoustic signal with a first control filter G1 calculated based on the input localization magnification n to generate a first adjusted acoustic signal. The second control filter unit is configured to adjust the first acoustic signal with a second control filter G2 calculated based on the input localization magnification n to generate a second adjusted acoustic signal. The second and third speakers are configured to generate second and third sounds according to the first and second adjusted acoustic signals, respectively.

Abstract: According to one embodiment, a pressure sensor includes a base, and a first sensor unit. The first sensor unit includes a first transducer thin film, a first strain sensing device and a second strain sensing device. The first strain sensing device includes a first magnetic layer, a second magnetic layer, and a first intermediate layer provided between the first and the second magnetic layers. The second strain sensing device is provided apart from the first strain sensing device on the first membrane surface and provided at a location different from a location of the barycenter, the second strain sensing device including a third magnetic layer, a fourth magnetic layer, and a second intermediate layer provided between the third and the fourth magnetic layers, the first and the second intermediate layers being nonmagnetic. The first and the second strain sensing devices, and the barycenter are in a straight line.

Abstract: According to an embodiment, a control filter coefficient is calculated in such a manner that a second spatial average of one or more complex sound pressure ratios at one or more target binaural positions when a first loudspeaker and a second loudspeaker emit a second acoustic signal and a first acoustic signal is approximated to a first spatial average of one or more complex sound pressure ratios at the one or more target binaural positions when a target virtual acoustic source emits the first acoustic signal.

Abstract: According to one embodiment, a sound field control apparatus is provided with a control filter and a calculation unit. The filter executes an FIR computation for an acoustic signal using coefficients to output a main signal and control signals. The unit calculates the main coefficient and the coefficients based on Spatial transmission characteristics and a sound increase factor n, to set a composite sound pressure from a main speaker and control speakers to a first area to be n times of a coming sound pressure from only the main speaker, and to set a composite sound pressure from the main speaker and control speakers to a second area to be equal to the coming sound pressure from only the main speaker.

Abstract: According to one embodiment, an acoustic reproduction device includes a loudspeaker unit, a loudspeaker rear chamber unit, and a port unit. The loudspeaker unit generates a sound wave. The loudspeaker rear chamber unit includes a chamber portion in which the loudspeaker unit is arranged, and at least one of a duct portion and a branch portion. The duct portion and the branch portion each have a volume, a cross-sectional area, and a length different from those of the chamber portion. A port unit is connected to the loudspeaker rear chamber unit and has a port to externally output a rear wave. The duct portion guides the rear wave from the loudspeaker unit up to the port unit.

Abstract: According to one embodiment, a sound image localization apparatus includes following units. The first signal generating unit is configured to generate a first acoustic signal. The first speaker is configured to generate a first sound according to the first acoustic signal. The input unit is configured to input a localization magnification n. The first control filter unit is configured to adjust the first acoustic signal with a first control filter G1 calculated based on the input localization magnification n to generate a first adjusted acoustic signal. The second control filter unit is configured to adjust the first acoustic signal with a second control filter G2 calculated based on the input localization magnification n to generate a second adjusted acoustic signal. The second and third speakers are configured to generate second and third sounds according to the first and second adjusted acoustic signals, respectively.

Abstract: A sheet conveying device includes: a feed unit that feeds sheets from a predetermined position; a conveying unit that conveys the sheets fed by the feed unit toward an image forming position at which images are to be formed on the respective sheets; and a registration unit that is provided at an upstream of the image forming position and positions the sheets by being bumped with the sheets conveyed by the conveying unit, wherein the feed unit and the registration unit are configured to operate so that a first timing at which a precedent sheet is bumped to the registration unit and a second timing at which a subsequent sheet is fed by the feed unit matches when a plurality of sheets are consecutively fed by the feed unit.

Abstract: In a sheet conveying mechanism, a first bulging space and a second bulging space are provided on a downstream side and an upstream side, respectively, of a conveying path. The second bulging space has a length L1 along the conveying path. The conveying path between the first and second bunging spaces is defined to have a length L2. The lengths L1 and L2 are set to satisfy a predetermined relationship with a frequency of noise propagating through the conveying path. The sheet conveying mechanism can inexpensively reduce noise generated inside the conveying path during sheet conveyance without hindering the conveyance of the sheet.