Patent application number | Description | Published |
20080317254 | NOISE CONTROL DEVICE - A noise control device according to the present invention comprises: four or more noise detectors each for detecting a plurality of noises arriving thereat, and outputting the noises as a noise signal; a control speaker for radiating, to a control point, a control sound based on each noise signal; and a filter section for signal-processing noise signals from the noise detectors by using filter coefficients which respectively correspond to the four or more noise detectors and which are set such that the control sound from the control speaker reduces the plurality of noises arriving at the control point, and for adding up all the signal-processed noise signals, and for outputting a resultant signal to the control speaker. The control point and the control speaker are provided within a polyhedral-shaped space whose apexes are placement positions of the noise detectors. | 12-25-2008 |
20090193895 | Sound field measuring method and sound field measuring device - A sound field measuring device according to the present invention uses a measurement signal which has at least one change point and whose frequency spectrum has a shape corresponding to a shape of a frequency spectrum of a background noise. This enables a sound field measurement, which is for measuring an impulse response or transfer function of a sound field space which is a linear time-invariant system to be measured, to be performed with a high S/N ratio over a wide frequency band. | 08-06-2009 |
20100027804 | NOISE CONTROL DEVICE - To provide a noise control device capable of eliminating a possibility that a noise arriving at a control point is increased as compared to a case where the noise control is not performed and capable of reducing the circuit scale thereof. The noise control device according to the present invention includes: a controlling noise detector for detecting a given arriving noise to output a controlling noise signal; a controlling filter section for signal-processing the controlling noise signal outputted from the controlling noise detector, by using a fixed filter coefficient which is preset, to output a control signal; a control speaker for reducing the given noise arriving at the control point, by emitting toward the control point a control sound based on the control signal outputted from the controlling filter section; a noise determination section for determining whether or not the given noise arriving at the control point is a noise corresponding to the fixed filter coefficient; and an output control section for stopping output of the control signal from the controlling filter section when the noise determination section determines that the given noise is not a noise corresponding to the fixed filter coefficient. | 02-04-2010 |
20100104110 | NOISE REDUCTION DEVICE AND NOISE REDUCTION SYSTEM - It includes a microphone for detecting noise emitted from a noise source, a noise controller for generating control sound signal to reduce noise detected by the microphone based on information from the microphone, and a speaker for outputting control sound based on control sound signal from the noise controller, wherein a plurality of microphones and speakers are arranged for each seat, and a plurality of microphones are arranged in higher density for each seat in a specific direction. | 04-29-2010 |
20100111317 | NOISE REDUCTION DEVICE - A noise reduction device, including a microphone for detecting noise, a noise controller for reversing the phase of noise detected by the microphone based on information outputted from the microphone, and a speaker for outputting sound based on information outputted from the noise controller, is arranged at a seat surrounded by a shell portion having a cavity, wherein a speaker is disposed in the cavity of the shell portion. | 05-06-2010 |
20100124341 | NOISE CONTROL DEVICE - A noise control device according to the present invention includes: a signal processor that detects a noise outputted from a noise source, and generates a control signal based on the noise; a control acoustic system that generates a control sound for canceling the noise, based on the control signal outputted from the signal processor; and an output correction section that corrects the control signal outputted from the signal processor, in a frequency band for which a noise control process time τ, which is a time period from when the noise is outputted from the noise source to pass through the signal processor and the control acoustic system to when the control sound reaches the control point, is larger than a noise transfer time T, which is a time period from when the noise is outputted from the noise source to when the noise reaches the control point via the noise transfer system (τ>T). | 05-20-2010 |
20100166202 | NOISE REDUCTION DEVICE - A noise control device includes the following structural elements. A signal memory records both of a noise signal supplied from a noise microphone and an error signal supplied from an error microphone. A filter coefficient calculator calculates a fixed filter coefficient of a control filter by using data recorded in the signal memory. A filter coefficient renewing section renews, at a given timing, a filter coefficient set at a fixed filter in a control filter to a filter coefficient read out from the filter coefficient calculator. | 07-01-2010 |
20100208911 | NOISE REDUCTION APPARATUS - In a noise reduction apparatus for controlling noise up to a predetermined upper limited frequency, a distance from a noise source to control point X is made larger than a distance obtained by subtracting a one-half wavelength from a distance, obtained by adding up a distance from the noise source to a noise detecting microphone, a distance corresponding to time as a sum of respective delay time of the noise detecting microphone, a noise controller, and a control speaker, and a distance from the control speaker to control point X, where one wavelength is a period corresponding to the upper limited frequency. | 08-19-2010 |
20120070020 | SPEAKER DEVICE, AUDIO CONTROL DEVICE, WALL ATTACHED WITH SPEAKER DEVICE - A speaker ( | 03-22-2012 |
20120314889 | SOUND IMAGE LOCALIZATION CONTROL APPARATUS - An audio signal high frequency component controlled in terms of directivity is reproduced, or an audio signal high frequency component compensated in terms of frequency characteristic or controlled in terms of directivity is reproduced, such that the reflected sound comes from a direction in which the high frequency component is intended to be localized. The sound pressure in a seat where a desired localization effect is not provided due to the arrangement of speakers is compensated such that the interaural amplitude level in the seat is equal to that of another seat. Thus, an equivalent level of localization effect is provided in a plurality of seats, especially for an audio signal high frequency component, without significantly increasing the number of the speakers. | 12-13-2012 |
20130034246 | DIFFRACTED SOUND REDUCTION DEVICE, DIFFRACTED SOUND REDUCTION METHOD, AND FILTER COEFFICIENT DETERMINATION METHOD - A diffracted sound reduction device includes: a reproduction speaker that outputs reproduced sound having properties indicated by an input signal; control speakers each of which reproduces corresponding one of control signals, the diffracted sound being a part of the reproduced sound and arriving at corresponding one of the control points except the control point at the listener's position; and control filters each of which filters the input signal to generate corresponding one of the control signals. Each of the control points faces a corresponding speaker from among the reproduction speaker and the control speakers. Each of the control filters generates the corresponding one of the control signals so that a sound pressure of the diffracted sound at corresponding one of the control points is lower than a sound pressure of direct sound that is a part of the reproduced sound which arrives at the control point of the listener's position. | 02-07-2013 |
20140056431 | SOUND FIELD CONTROL APPARATUS AND SOUND FIELD CONTROL METHOD - A sound field control apparatus appropriately presenting desired sound in a listening area and sufficiently reducing the sound in a nearby area without constraint on configuration arrangement includes: a listening compensation filter processing a signal from a sound source using a control characteristic and outputting the signal to a second speaker; and a control filter processing the signal from the listening compensation filter using a control characteristic and outputting the signal to a first speaker. The characteristic of the control filter is a first previously-set characteristic whereby reproduced sound from the second speaker is reduced by reproduced sound from the first speaker at a first control position. The characteristic of the listening compensation filter is a second previously-set characteristic whereby sound having a predetermined target acoustic characteristic is presented by reproduced sounds from the first and second speakers at a second control position. | 02-27-2014 |