Patent application number | Description | Published |
20100272269 | CENTER CHANNEL POSITIONING APPARATUS - A center channel positioning apparatus is provided, which does not cause strange feeling in sound quality even at a position apart from an original listener position. | 10-28-2010 |
20110026720 | SIGNAL PROCESSING APPARATUS AND SIGNAL PROCESSING METHOD - A surround effect in low-tone range can be improved when speakers to be positioned in front of a listener are used to realize a surround sound. A left surround signal extracting part | 02-03-2011 |
20110268285 | SOUND IMAGE LOCALIZATION ESTIMATING DEVICE, SOUND IMAGE LOCALIZATION CONTROL SYSTEM, SOUND IMAGE LOCALIZATION ESTIMATION METHOD, AND SOUND IMAGE LOCALIZATION CONTROL METHOD - Sound pressure acquisition element integrate by time and convert into logarithms a plurality of inputted sound signals to acquire each sound pressure corresponding to the plurality of sound signals. Normalizing element normalizes each sound pressure acquired by the sound pressure acquisition element. Linear sum calculating element calculates a linear sum of each sound pressure normalized by the normalizing element using a plurality of parameters which differ for each frequency range of the sound signals. | 11-03-2011 |
20110268298 | SOUND FIELD CORRECTING DEVICE - At least two speakers are arranged in the left-right direction, and the measurement signal generating unit generates the measurement signal from the two speakers. The measurement signal outputting unit outputs the measurement signal. The measurement signal collecting unit collects the measurement signal for the left-right direction from at least two positions along the left-right direction axis in the acoustic space. The delay correcting unit performs the delay adjustment for any one of the speakers in the acoustic space, based on information that the measurement signal collecting unit obtains by collecting the measurement signal for the left-right direction, until the level difference in the left-right direction becomes equal to or smaller than the predetermined value. The sound field correcting device collects the measurement signal from two positions along the left-right direction axis, and reduces the level difference in the left-right direction based on the information obtained by collecting the sound. | 11-03-2011 |
20120033821 | ACTIVE VIBRATION NOISE CONTROL DEVICE - An active vibration noise control device having a pair of speakers, including: a basic signal generating unit generating a basic signal based on a vibration noise frequency; an adaptive notch filter generating a first control signal provided to one speaker using a first filter coefficient and generating a second control signal provided to the other speaker using a second filter coefficient to cancel the generated vibration noise; a microphone detecting cancellation error between the vibration noise and the control sounds and outputting an error signal; a reference signal generating unit generating a reference signal based on a transfer function from the speakers to the microphone; a filter coefficient updating unit updating first and second filter coefficients, minimize the error signal; and a phase difference limiting unit limiting a phase difference between control sounds generated by different speakers. Therefore, it becomes possible to appropriately ensure a uniform and wide noise-cancelled area. | 02-09-2012 |
20120195439 | ACTIVE VIBRATION NOISE CONTROL DEVICE - An active vibration noise control device is preferably used for cancelling a vibration noise by making a speaker generate a control sound. The active vibration noise control device includes a step-size parameter changing unit which changes a step-size parameter used for updating a filter coefficient. The step-size parameter changing unit calculates a parameter-for-change based on the filter coefficient updated by using a basic step-size parameter, and changes the basic step-size parameter by a minimum value in the previously calculated parameter-for-change. Therefore, it is possible to appropriately change the step-size parameter by using the minimum value of the parameter-for-change. Hence, it becomes possible to effectively suppress a divergence of an adaptive notch filter due to a secular change of the speaker. | 08-02-2012 |
20120300955 | ACTIVE VIBRATION NOISE CONTROL DEVICE - An active vibration noise control device cancels vibration noise by making plural speakers generate control sounds. The active vibration noise control device selects one or more speakers which output the control sounds, from plural speakers, based on a relationship between (1) a first phase difference which corresponds to a difference between phase characteristics of the vibration noise from a vibration noise source to an evaluation point and phase characteristics of the vibration noise from the vibration noise source to a pseudo evaluation point and (2) a second phase difference for each of the plural speakers corresponding to a difference between phase characteristics of the control sound from the speaker to the evaluation point and phase characteristics of the control sound from the speaker to the pseudo evaluation point. Therefore, it stably decreases the vibration noise at the pseudo evaluation point independently of a frequency band of the vibration noise. | 11-29-2012 |
20130044891 | ACTIVE VIBRATION NOISE CONTROL DEVICE - The disclosed active vibration noise control device is suitable for use in cancelling out vibration noise by outputting control noise from a plurality of speakers. When a vibration noise frequency is in a dip bandwidth, the active vibration noise control device alters the step size parameters used to update the filter coefficient at at least one filter coefficient update means from among a plurality of filter coefficient update means. Thus, the filter coefficient update speed can be retarded in unstable dip bandwidths, enabling loss in silencing effect which occurs during dip characteristics to be appropriately reduced. | 02-21-2013 |
20130279712 | ACTIVE VIBRATION NOISE CONTROL DEVICE, ACTIVE VIBRATION NOISE CONTROL METHOD AND ACTIVE VIBRATION NOISE CONTROL PROGRAM - An active vibration noise control device obtains error signals corresponding to a cancellation error between vibration noise and control sounds generated by multiple speakers, from microphone(s), and actively controls the vibration noise. A basic signal generating unit generates a basic signal based on a vibration noise frequency. An adaptive notch filter unit generates control signals provided to each of the multiple speakers by applying a filter coefficient to the basic signal. A reference signal generating unit generates a reference signal from the basic signal based on multiple transfer characteristics from the multiple speakers to the one or more microphones. A filter coefficient updating unit updates the filter coefficient used by the adaptive notch filter unit so as to minimize the error signals. A controlling unit changes amplitude of the control signals of the speakers based on a similarity between the transfer characteristics and characteristics of the vibration noise. | 10-24-2013 |
20150043746 | SOUND REPRODUCTION DEVICE - The sound reproduction device is applied to an acoustic space such as a passenger compartment, and controls the levels of the reproduced sounds at two evaluation points set at the seats in the passenger compartment, for example. Specifically, the sound reproduction device controls the phase of the one channel sound signal inputted from external and supplies it to the pair of speakers. The phase control is performed such that the sum of reproduced sound levels at the two evaluation points becomes larger than the sum of the reproduced sound levels at the two evaluation points in a case where the sound signal is reproduced by only one of the pair of speakers, in an entire audible band | 02-12-2015 |