Abstract: An ultrasonic speaker system has a first variable gain block, a modulation block, a second variable gain block, an ultrasonic actuator, and a controller, wherein the controller controls gain of the first variable gain block so that a modulation degree of a modulated signal becomes a predetermined value, and when the controller raises the gain of the first variable gain block, the controller lowers the gain of the second variable gain block, while when the controller lowers the gain of the first variable gain block, the controller raises the gain of the second variable gain block.

Abstract: Provided is a sound reproduction device including: a first loudspeaker having directionality utilizing a parametric effect; a second loudspeaker having directionality broader than that of the first loudspeaker; an orientation adjustment unit configured to change an orientation of the first loudspeaker; an information obtaining device configured to obtain positional information of a listener; and a drive controller electrically connected to the first loudspeaker, the second loudspeaker, the orientation adjustment unit, and the information obtaining device, and configured to control the orientation of the first loudspeaker based on the positional information of the listener.

Abstract: Provided is a sound reproduction device including a loudspeaker and a superdirective speaker. The loudspeaker is configured so that a sound pressure of audible sound produced therefrom decreases as the sound travels farther away from the loudspeaker. The superdirective speaker is configured so that a sound pressure of audible sound produced therefrom has a peak at a predetermined distance from the superdirective speaker, and is configured to use an ultrasonic wave as a carrier wave. The loudspeaker and the superdirective speaker are positioned such that a loudspeaker sound field of the audible sound produced from the loudspeaker and a superdirective speaker sound field of the audible sound produced from the superdirective speaker overlap with each other at a position of a listener.

Abstract: An ultrasonic speaker system has a first variable gain block, a modulation block, a second variable gain block, an ultrasonic actuator, and a controller, wherein the controller controls gain of the first variable gain block so that a modulation degree of a modulated signal becomes a predetermined value, and when the controller raises the gain of the first variable gain block, the controller lowers the gain of the second variable gain block, while when the controller lowers the gain of the first variable gain block, the controller raises the gain of the second variable gain block.

Abstract: A sound reproduction device includes a modulator having an output terminal for outputting a modulated carrier wave signal obtained by modulating a carrier wave signal in a ultrasonic band with an audible sound signal, a super-directivity loudspeaker connected to the output terminal, a capacitor connected between a ultrasonic wave source and a ground, first and second current detectors for detecting currents flowing through the super-directivity loudspeaker and the capacitor, a high-pass filter for outputting a filtered signal obtained by eliminating a low-frequency band component of the current detected by the first current detector, and a differential amplifier unit for outputting a signal corresponding to a difference between the filtered signal and the current detected by the second current detector. The ultrasonic wave source is configured to output the carrier wave signal such that the signal output from the differential amplifier unit is constant.

Abstract: Provided is a sound reproduction device including a loudspeaker and a superdirective speaker. The loudspeaker is configured so that a sound pressure of audible sound produced therefrom decreases as the sound travels farther away from the loudspeaker. The superdirective speaker is configured so that a sound pressure of audible sound produced therefrom has a peak at a predetermined distance from the superdirective speaker, and is configured to use an ultrasonic wave as a carrier wave. The loudspeaker and the superdirective speaker are positioned such that a loudspeaker sound field of the audible sound produced from the loudspeaker and a superdirective speaker sound field of the audible sound produced from the superdirective speaker overlap with each other at a position of a listener.

Abstract: In a directional loudspeaker, an audible sound signal that is modulated with a carrier wave in the ultrasonic wave band is input to a piezoelectric element, and thereby a diaphragm having the piezoelectric element is vibrated and a sound wave is generated. In such a directional loudspeaker, the diaphragm is fixed to a fixed part via a plurality of beams disposed along the outer circumference of the diaphragm.

Abstract: A sound reproducing device includes parametric speakers disposed to a display, a loudspeaker, drivers, a human-body sensor, and a controller. The loudspeaker has a wider directivity than the parametric speakers. The drivers change directions of the parametric speakers, respectively. The parametric speakers and the drivers constitute at least two parametric speaker units each composed of respective one of the parametric speakers and respective one of the drivers. The controller reproduces sound information based the number of persons in front of the display detected from an output from the human-body senor. The sound reproducing device reduces the possibility for a number of persons to hear the sound noisily, and allows drawing more attention to the content, e.g. an advertisement.

Abstract: A sound reproduction device includes a superdirective speaker having a first surface, and an attachment part having a second surface opposed to the first surface. The first surface has a convex face, and the second surface has a concave face which can come into contact with the convex face. A curvature of the convex face is set larger than that of the concave face. A direction of emitting a sound wave of the superdirective speaker can be adjusted by making the convex face move along the concave face.

Abstract: Provided is a sound reproduction device including a loudspeaker and a superdirective speaker. The loudspeaker is configured so that a sound pressure of audible sound produced therefrom decreases as the sound travels farther away from the loudspeaker. The superdirective speaker is configured so that a sound pressure of audible sound produced therefrom has a peak at a predetermined distance from the superdirective speaker, and is configured to use an ultrasonic wave as a carrier wave. The loudspeaker and the superdirective speaker are positioned such that a loudspeaker sound field of the audible sound produced from the loudspeaker and a superdirective speaker sound field of the audible sound produced from the superdirective speaker overlap with each other at a position of a listener.

Abstract: A sound reproducing device includes parametric speakers disposed to a display, a loudspeaker, drivers, a human-body sensor, and a controller. The loudspeaker has a wider directivity than the parametric speakers. The drivers change directions of the parametric speakers, respectively. The parametric speakers and the drivers constitute at least two parametric speaker units each composed of respective one of the parametric speakers and respective one of the drivers. The controller reproduces sound information based the number of persons in front of the display detected from an output from the human-body senor. The sound reproducing device reduces the possibility for a number of persons to hear the sound noisily, and allows drawing more attention to the content, e.g. an advertisement.

Abstract: An sound reproducing apparatus is configured such that a correction amount is calculated on the basis of a masking model, determiner for determining a correction parameter correcting input signal so as to be natural for human ears to hear on the basis of the calculated correction amount is provided, and a characteristic of correction filter is changed on the basis of a result of determiner when inputting vehicle speed information.

Abstract: A sound reproducing apparatus is provided with a circuit comprising a first secondary phase shifter in a front stage of at least one of channels among a first power amplifier, a second power amplifier and a third power amplifier, and a second secondary phase shifter and an adder in at least one of remaining channels for providing an output by adding output signals of a music signal source and the second secondary phase shifter. The apparatus of this structure eliminates phase interferences between a center speaker and right and left speakers by controlling sound waves generated by the center speaker, thereby achieving excellent reproduction of music.

Abstract: The sound reproducing apparatus for use with a signal source comprises, a first output unit connected to the signal source via a first power amplifier, a first phase shifter connected to the signal source, a second output unit connected to the first phase shifter via a second power amplifier, a second phase shifter connected to the signal source, a third output unit connected to the second phase shifter via a third power amplifier, a fourth phase shifter connected to a third phase shifter, and a fourth output unit connected to the fourth phase shifter via a fourth power amplifier, wherein the first output unit and the second output unit are in right and left relation with each other, the third output unit and the fourth output unit are in right and left relation with each other, a group of the first output unit and the second output unit and a group of the third output unit and the fourth output unit are in front and rear relation with each other. The vehicle is equipped with the sound reproducing apparatus.

Abstract: A sound reproduction apparatus reproduces a sound wave at a listening position. The sound reproduction apparatus includes a compensation processing unit for compensating an audible band signal having an audible band frequency, a carrier signal oscillator for generating a carrier signal, a modulator for outputting a modulated signal obtained by modulating the carrier signal based on the audible band signal compensated by the compensation processing unit, and a sound emission unit for outputting a sound wave depending on the modulated signal output from the modulator. The compensation processing unit compensates the audible band signal based on a distance from the sound emission unit to the listening position. This sound reproduction apparatus can reproduce the original audible band signal with a high fidelity regardless of the listening position.

Abstract: In a sound reproducing apparatus, part of a frequency band where mode-coupled vibration can be excited is regarded as a carrier frequency. A frequency of mode coupling, with a low rate of change in vibration displacement with respect to the frequency, is regarded as a carrier signal so that a signal in an audible band which is outputted from an audible band signal source can be demodulated and reproduced with stable sound pressure in a broad frequency band.

Abstract: A drunk driving detection system to be incorporated in a vehicle includes a steering wheel, a film, a pair of contact detection electrodes, an alcohol sensor, and a control circuit. The steering wheel is provided with an opening in a portion to be grasped by a driver. The film is liquid-impermeable and air-permeable, and covers the first opening. The contact detection electrodes are provided on the film. The alcohol sensor is provided in a space in communication with the opening. The control circuit is connected to the contact detection electrodes and the alcohol sensor, and measures the resistance between the contact detection electrodes. When the resistance is within a predetermined range, the control circuit determines that the driver is in contact with the film and detects an alcohol drinking condition of the driver based on the output from the alcohol sensor.

Abstract: An sound reproducing apparatus is configured such that a correction amount is calculated on the basis of a masking model, determiner for determining a correction parameter correcting input signal so as to be natural for human ears to hear on the basis of the calculated correction amount is provided, and a characteristic of correction filter is changed on the basis of a result of determiner when inputting vehicle speed information.

Abstract: The sound reproducing apparatus for use with a signal source comprises, a first output unit connected to the signal source via a first power amplifier, a first phase shifter connected to the signal source, a second output unit connected to the first phase shifter via a second power amplifier, a second phase shifter connected to the signal source, a third output unit connected to the second phase shifter via a third power amplifier, a fourth phase shifter connected to a third phase shifter, and a fourth output unit connected to the fourth phase shifter via a fourth power amplifier, wherein the first output unit and the second output unit are in right and left relation with each other, the third output unit and the fourth output unit are in right and left relation with each other, a group of the first output unit and the second output unit and a group of the third output unit and the fourth output unit are in front and rear relation with each other. The vehicle is equipped with the sound reproducing apparatus.

Abstract: A drunk driving detection system to be incorporated in a vehicle includes a steering wheel, a film, a pair of contact detection electrodes, an alcohol sensor, and a control circuit. The steering wheel is provided with an opening in a portion to be grasped by a driver. The film is liquid-impermeable and air-permeable, and covers the first opening. The contact detection electrodes are provided on the film. The alcohol sensor is provided in a space in communication with the opening. The control circuit is connected to the contact detection electrodes and the alcohol sensor, and measures the resistance between the contact detection electrodes. When the resistance is within a predetermined range, the control circuit determines that the driver is in contact with the film and detects an alcohol drinking condition of the driver based on the output from the alcohol sensor.