Class / Patent application number | Description | Number of patent applications / Date published |
381710200 | Acoustic, nonairborne vibration sensing or counterwave emission | 18 |
20080267421 | REDUCING CHASSIS INDUCED NOISE WITH A MICROPHONE ARRAY - A system for reducing noise induced from a chassis is described. The system comprises a signal processing engine, a first microphone connected to a chassis and communicatively coupled to the signal processing engine, a dampener connected to the chassis, and a second microphone connected to the dampener and communicatively coupled to the signal processing engine. | 10-30-2008 |
20090041258 | Noise reduction apparatus - Effective reduction is made of direct sound or diffracted sound of a noise propagating from plural directions. Three microphones ( | 02-12-2009 |
20090060216 | System and method for localized noise cancellation - A system and method for localized noise cancellation. An audio signal is received from an environment in close proximity to a primary area. The audio signal is processed to generate an inverse signal of the audio signal. The inverse signal is broadcast within the primary area to destructively interfere with the audio signal. The inverse signal is configured to prevent the audio signal from being broadcast through a telephone conversation ongoing in the primary area. | 03-05-2009 |
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 |
20100260347 | REFLECTION CANCELLING BOUNDARY MICROPHONES AND AMPLIFICATION SYSTEMS INCORPORATING REFLECTION CANCELLING BOUNDARY MICROPHONES - Reflection cancelling boundary microphones are described in which a microphone capsule is mounted within the pressure zone of a vibrating surface and the microphone is tuned in such a way as to cancel pressure waves reflected by the surface while admitting pressure waves generated by the vibration of the surface. One embodiment of the invention includes a microphone capsule configured to be mounted within the pressure zone of a vibrating surface. In addition, the microphone is tuned to cancel pressure waves reflected by the surface while admitting pressure waves generated by the vibration of the surface. | 10-14-2010 |
20100284546 | Active noise control algorithm that requires no secondary path identification based on the SPR property - A control system for reducing noise or vibration in a target zone. The noise or vibration is produced by a source and transferred to the target zone by a main path. The control system is provided with an actuator, at least one error sensor and a controller. The actuator is positioned to deliver actuated signals into at least a portion of the target zone. The at least one error sensor monitors the residual noise or vibration power in the target zone and produces an error signal representative thereof. The controller receives a reference signal representative of noise or vibration produced by the source, and the error signal representative of the residual noise power in the target zone. The controller analyzes sub-bands of the reference signal and the error signal without identification of a secondary path, and provides drive signals to the actuator to cause the actuator to deliver the actuated signals into the target zone so as to reduce the residual noise power in the target zone. | 11-11-2010 |
20130195282 | ACTIVE VIBRATION NOISE CONTROL DEVICE - An active vibration noise control device is preferably used for canceling a vibration noise by making a speaker generate a control sound. Concretely, the active vibration noise control device includes an attenuating unit which attenuates a control signal generated by an adaptive notch filter, and provides the attenuated control signal to the speaker, when amplitude of a filter coefficient is larger than a threshold. Therefore, it is possible to suppress continuous ups and downs of the filter coefficient during an occurrence of an abnormality. Hence, it becomes possible to appropriately suppress an occurrence of a cyclic abnormal sound and an increase in the vibration noise during the occurrence of the abnormality. | 08-01-2013 |
20130216059 | APPARATUS AND METHOD FOR REDUCING DIGITAL NOISE OF AUDIO SIGNAL - Provided are an apparatus and method for reducing digital noise. The digital noise reducing apparatus includes: a clarified signal generator configured to generate a clarity improvement pattern for increasing an energy ratio of an early reflection region with respect to all reverberations for a received audio source signal, to convolve the clarity improvement pattern with the audio source signal, and to output an audio source signal convolved the audio source signal with the clarity improvement pattern; an early reflection generator configured to output an early reflection signal convolved the audio source signal with an early reflection pattern; a late reverberation generator configured to receive the audio source signal, and to generate a late reverberation signal for attenuating digital noise of the audio source signal; and a noise attenuator configured to generate an audio signal added the early reflection signal and the late reverberation signal to the audio source signal. | 08-22-2013 |
20140205106 | INSTRUMENT AMPLIFICATION SYSTEMS INCORPORATING REFLECTION CANCELLING BOUNDARY MICROPHONES AND MULTIBAND COMPRESSION - Instrument amplification systems incorporating reflection cancelling boundary microphones and multiband compression in accordance with embodiments of the invention are disclosed. In one embodiment, an amplification system includes a microphone configured to generate an audio signal based upon acoustic waves within the instrument including audio content within a low frequency band including a fundamental resonant frequency of the instrument, a middle frequency band including at least one harmonic frequency of the instrument, and an upper frequency band, where the frequency response characteristics of acoustic waves generated within the instrument in the low frequency band differ from the characteristics of acoustic waves generated outside of the instrument, and an electronic preamplifier system configured to provide the audio content within the low frequency band to a low frequency band amplification circuit that applies compression to provide audio content having frequency characteristics corresponding to the characteristics of acoustic waves generated outside of the instrument. | 07-24-2014 |
20140301558 | DUAL STAGE NOISE REDUCTION ARCHITECTURE FOR DESIRED SIGNAL EXTRACTION - Systems and methods are described to reduce undesired audio. An adaptive noise cancellation unit receives a main signal and a reference signal. The main signal has a main signal-to-noise ratio; the reference signal has a reference signal-to-noise ratio. The reference signal-to-noise ratio is less than the main signal-to-noise-ratio. The adaptive noise cancellation unit reduces undesired audio from the main signal. An output signal from the adaptive noise cancellation unit is input to a single channel noise cancellation unit. The single channel noise cancellation unit further reduces undesired audio from the output signal to provide mostly desired audio. A filter control creates a control signal from the main signal and the reference signal to control filtering in the adaptive noise cancellation unit and to control filtering in the single channel noise cancellation unit. | 10-09-2014 |
20140355776 | INTERESTED AUDIO SOURCE CANCELLATION METHOD AND VOICE RECOGNITION METHOD AND VOICE RECOGNITION APPARATUS THEREOF - Provided are an interested audio source cancellation method, a voice recognition method using the interested audio source cancellation method, computer-readable recording media recording programs for implementing the methods, and a voice recognition apparatus for performing voice recognition by using the interested audio source cancellation method. The interested audio source cancellation method includes steps of: receiving input mixed signals from two microphones and transforming the signals into a time-frequency domain through short-term Fourier transformation; setting an interested audio source cancellation vector for cancelling an interested audio source signal from the input mixed signals in the time-frequency domain; and generating a mixed noise signal by cancelling the interested audio source signal from the input mixed signals by using the interested audio source cancellation vector. | 12-04-2014 |
20140376732 | DEVICE ECHO CANCELLATION - A Device Echo Cancellation system and process are disclosed. According to one embodiment, the present invention comprises an input audio source that is converted to a digital signal via a PCM convertor where the amplitude of the input audio source is sampled at regular intervals and translated into digital PCM audio. The resulting PCM audio is analyzed for its dynamic and harmonic content. Corrective sound waves are then generated that reduce the repetition of the original audio (echoes). The corrective sound waves are applied to the repeating audio echoes to create corrected sound waves. The corrected audio is then outputted from the system. The analyzing step of the Device Echo Cancellation process of the present invention comprises performing an evaluation of the PCM audio for dynamic and harmonic content; identifying repetitive harmonic content (echoes) of the PCM audio; determining a scale based on the ratio of the amplitude of the first repeat harmonic to the amplitude of the input PCM audio; generating sound waves with descending amplitude levels according to the determined scale; and phase shifting the newly generated sound waves to generate corrective sound waves. The phase shift of the inventive Device Echo Cancellation process is 90 to 180 degrees. | 12-25-2014 |
20150030172 | Inter-Channel Coherence Reduction for Stereophonic and Multichannel Acoustic Echo Cancellation - In an audio system having acoustic echo, incoming audio signals are decorrelated by applying both phase modulation and amplitude modulation. The resulting decorrelated signals are rendered by loudspeakers, and co-located microphones generate outgoing audio signals that include echo signals caused by the existence of acoustic echo paths from the loudspeakers to the microphones. Acoustic echo cancellation (AEC) is applied to the outgoing audio signals to reduce the amount of echo in those signals. Decorrelating the incoming audios signals using amplitude modulation in addition to phase modulation can increase the effectiveness of the AEC processing. In a frequency-domain implementation, the amount of amplitude modulation can be different for different frequency bands (e.g., greater amplitude modulation for lower frequencies corresponding to human speech and/or no amplitude modulation for higher frequencies). | 01-29-2015 |
20150063581 | ACTIVE NOISE REDUCTION DEVICE AND ACTIVE NOISE REDUCTION METHOD - An active noise reduction device is used with a secondary noise source that generates a secondary noise and an error signal source that outputs an error signal corresponding to a residual sound caused by interference between the secondary noise and a noise. A μ-adjustment unit calculates a step-size parameter for updating a filter coefficient of an adaptive filter by multiplying a standard step-size parameter by a ratio of a standard representative input value corresponding to amplitude of a signal to a representative input value corresponding to the amplitude of the signal. | 03-05-2015 |
20150358729 | SYSTEM FOR CONTROLLING NOISE IN A WINDOW ASSEMBLY - A system for controlling noise in a fenestration assembly (e.g., a window) includes a fenestration assembly with at least one glazing and a frame. The at least one glazing has a surface. At least one sensor is coupled to the at least one glazing and is configured to generate noise detection signals. An actuator is positioned on the surface of the at least one glazing and has a plurality of regions. A controller is coupled to the sensor and the actuator and is configured to control each of the regions of the actuator to generate a different frequency based on the noise detection signals. Alternatively, each of the regions may be controlled to generate a frequency with a different phase shift based on the noise detection signals. | 12-10-2015 |
20160088380 | WEARABLE AUDIO DEVICE - In one embodiment, a device includes at least one transducer configured to vibrate within a first frequency range to generate a signal audible by a wearer of the device. The device includes the first material, which has an acoustic impedance at one or more frequencies within the first frequency range that is substantially similar to an acoustic impedance of the wearer's skin at the one or more frequencies. The device includes a second material that has an acoustic impedance at one or more frequencies within the first frequency range that substantially differs from an acoustic impedance of an environment of the device. | 03-24-2016 |
20160203813 | ACOUSTIC DEVICE CAPABLE OF PRODUCING ACTIVE NOISE REDUCTION | 07-14-2016 |
20160379619 | WIRELESS AIRCRAFT, METHOD OF CANCELLING NOISE, PROGRAM FOR WIRELESS AIRCRAFT - The present invention is to provide a wireless aircraft, a method of cancelling noise, and a program for the wireless aircraft, which are capable of maintaining the flight performance of the aircraft and decreasing noises. The wireless aircraft | 12-29-2016 |