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: 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: 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: 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 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 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 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: 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 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 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 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: 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.

Abstract: Characteristics of spatial transmission from a speaker to a microphone contained in a remote controller and set in a listening area and in a non-listening area are measured. A plurality of different types of sound field control effects is calculated on the basis of the spatial transmission characteristics to predict the plurality of types of sound field control effects. The plurality of types of sound field control effects is displayed and presented to a user. The speaker is driven by using a control sound source corresponding to one sound field control effect selected from the plurality of types of sound field control effects by the user operating the remote controller to perform effective sound field control in the listening area and in the non-listening area.

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.