Abstract: An active noise reduction device includes: a reference signal input terminal that receives a reference signal outputted by a reference signal source and having a correlation with noise in a space in an automobile, the reference signal source being attached to the automobile; a test signal source that outputs a test signal to a loudspeaker attached to the automobile, the loudspeaker being used to output a canceling sound for reducing the noise; and an anomaly determiner that determines whether the reference signal source has an anomaly, based on the reference signal inputted from the reference signal source to the reference signal input terminal when the test signal is outputted to the loudspeaker.

Abstract: An active noise reduction device includes: a reference signal input terminal that receives a reference signal from a reference signal source attached to an automobile; a simulated vibration transfer characteristics filter unit that generates a second signal by correcting, using simulated vibration transfer characteristics, a first signal for outputting, from a loudspeaker attached to the automobile, a sound different from a canceling sound, the simulated vibration transfer characteristics simulating vibration transfer characteristics from the loudspeaker to the reference signal source; a first subtracter that outputs a corrected reference signal obtained by subtracting the second signal generated, from the reference signal received by the reference signal input terminal; and an adaptive filter unit that applies an adaptive filter to the corrected reference signal outputted from the first subtracter to generate a canceling signal to be used to output the canceling sound.

Abstract: An active noise reduction device includes: a reference signal input terminal that receives a reference signal outputted by a reference signal source and having a correlation with noise in a space in an automobile, the reference signal source being attached to the automobile; a test signal source that outputs a test signal to a loudspeaker attached to the automobile, the loudspeaker being used to output a canceling sound for reducing the noise; and an anomaly determiner that determines whether the reference signal source has an anomaly, based on the reference signal inputted from the reference signal source to the reference signal input terminal when the test signal is outputted to the loudspeaker.

Abstract: An active noise reduction device includes: a reference signal input terminal that receives a reference signal from a reference signal source attached to an automobile; a simulated vibration transfer characteristics filter unit that generates a second signal by correcting, using simulated vibration transfer characteristics, a first signal for outputting, from a loudspeaker attached to the automobile, a sound different from a canceling sound, the simulated vibration transfer characteristics simulating vibration transfer characteristics from the loudspeaker to the reference signal source; a first subtracter that outputs a corrected reference signal obtained by subtracting the second signal generated, from the reference signal received by the reference signal input terminal; and an adaptive filter unit that applies an adaptive filter to the corrected reference signal outputted from the first subtracter to generate a canceling signal to be used to output the canceling sound.

Abstract: An active noise reduction device includes an impulsive signal generator that generates an impulsive signal, a signal output terminal that outputs the impulsive signal to a loudspeaker, and a signal detector that detects a rising signal and a falling signal from a microphone signal outputted from a microphone collecting sound. The device also includes a connection determiner that determines, based on respective peak values of the rising signal detected and the falling signal detected, whether or not the loudspeaker is connected to the signal output terminal. The device further includes a polarity determiner that determines a connection polarity between the loudspeaker and the signal output terminal based on respective timings of the rising signal and the falling signal with respect to the impulsive signal, when it is determined that the loudspeaker is connected to the signal output terminal.

Abstract: An active noise reduction device includes: an impulsive signal generator that generates an impulsive signal; a signal output unit that outputs the impulsive signal to a loudspeaker; a signal detector that detects a rising signal and a falling signal from a microphone signal outputted from a microphone collecting sound; a connection determiner that determines, based on respective peak values of the rising signal detected and the falling signal detected, whether or not the loudspeaker is connected to the signal output unit; and a polarity determiner that determines a connection polarity between the loudspeaker and the signal output unit based on respective timings of the rising signal and the falling signal with respect to the impulsive signal, when it is determined that the loudspeaker is connected to the signal output unit.

Abstract: A noise masking device includes: an acquisition unit that acquires (i) frequency information indicating a frequency of a noise in a vehicle or frequency-correlated information correlated to the frequency and (ii) vehicle information relating to a characteristic of the noise; a signal source that generates a masker signal for outputting a masker sound that masks the noise in the vehicle; a pitch-shifting unit that pitch-shifts the masker signal according to the frequency information or the frequency-correlated information acquired by the acquisition unit to generate a pitch-shifted masker signal; an adjustment unit that performs, on the pitch-shifted masker signal, an adjustment according to the vehicle information acquired by the acquisition unit to generate an adjusted masker signal; and an output unit that outputs the adjusted masker signal as the masker sound.

Abstract: Provided is a sound masking device that can effectively mask a noise at a predetermined position in a vehicle. Sound masking device includes: information acquisition unit that acquires frequency information indicating a frequency of a noise; signal source that generates a masker signal in order to output a masker sound masking the noise; pitch shifting unit that performs pitch shifting on the masker signal according to the frequency information that has been acquired; first corrector that performs correction on the masker signal after the pitch shifting according to the predetermined position; and output unit that outputs the masker signal after the correction.

Abstract: A noise masking device includes: an acquisition unit that acquires (i) frequency information indicating a frequency of a noise in a vehicle or frequency-correlated information correlated to the frequency and (ii) vehicle information relating to a characteristic of the noise; a signal source that generates a masker signal for outputting a masker sound that masks the noise in the vehicle; a pitch-shifting unit that pitch-shifts the masker signal according to the frequency information or the frequency-correlated information acquired by the acquisition unit to generate a pitch-shifted masker signal; an adjustment unit that performs, on the pitch-shifted masker signal, an adjustment according to the vehicle information acquired by the acquisition unit to generate an adjusted masker signal; and an output unit that outputs the adjusted masker signal as the masker sound.

Abstract: Provided is a sound masking device that can effectively mask a noise at a predetermined position in a vehicle. Sound masking device includes: information acquisition unit that acquires frequency information indicating a frequency of a noise; signal source that generates a masker signal in order to output a masker sound masking the noise; pitch shifting unit that performs pitch shifting on the masker signal according to the frequency information that has been acquired; first corrector that performs correction on the masker signal after the pitch shifting according to the predetermined position; and output unit that outputs the masker signal after the correction.

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: 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: 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: 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: 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 sound reproducing apparatus is structured to use a first dividing circuit and a determining circuit to analyze a frequency characteristic of an inputted signal and to output a signal adjusted by a first adjusting circuit to have a prescribed frequency characteristic by a switching by a switch circuit. Thus, when signals having different frequency characteristics are inputted, frequency characteristics of the input signals can be automatically adjusted without using an external signal and channels having different frequency characteristics can be reproduced by a single system to provide good speaker-reproduced sound.