Class / Patent application number | Description | Number of patent applications / Date published |
381710120 | Algorithm or formula (e.g., LMS, Filtered-X, etc.) | 15 |
20080304678 | AUDIO TIME SCALE MODIFICATION ALGORITHM FOR DYNAMIC PLAYBACK SPEED CONTROL - A modified synchronized overlap add (SOLA) algorithm for performing high-quality, low-complexity audio time scale modification (TSM) is described. The algorithm produces good output audio quality with a very low complexity and without producing additional audible distortion during dynamic change of the audio playback speed. The algorithm may achieve complexity reduction by performing the maximization of normalized cross-correlation using decimated signals. By updating the input buffer and the output buffer in a precise sequence with careful checking of the appropriate array bounds, the algorithm may also achieve seamless audio playback during dynamic speed change with a minimal requirement on memory usage. | 12-11-2008 |
20090003617 | Noise cancellation for buildings and/or structures - A noise cancellation system for a building ( | 01-01-2009 |
20090086989 | Method and System for Providing Fast and Accurate Adaptive Control Methods - In accordance with a particular embodiment of the present invention, a method is offered that includes providing a low-pass filter in an adaptive filter architecture employing a fast steepest descent method. The method further includes decomposing an error signal, injecting a small change to one or more weight parameters for a linear combiner, measuring changes in an error correlation vector, and calculating one or more gradients, wherein the gradients are processed by the low-pass filter. In more particular embodiments, one or more of the gradients are processed by the low-pass-filter in order to remove measurement noise and improve accuracy. In addition, a real gradient of the error correlation vector is monitored such that adaptations can be made due to non-linearity and non-constant characteristics of a channel. The low-pass filter may be replaced with a Kalman Filter for faster convergence. | 04-02-2009 |
20090086990 | ACTIVE NOISE CONTROL USING BASS MANAGEMENT - An active noise cancellation system reduces, at a listening position, the power of a noise signal being radiated from a noise source to the listening position. The system includes an adaptive filter that receives a reference signal representing the noise signal, and provides a compensation signal. A bass management unit receives the compensation signal and applies a phase shift to the compensation signal to provide a phase shifted compensation signal. A first acoustic radiator receives the phase shifted compensation signal and radiates audio indicative thereof to the listening position. A second acoustic radiator receives the compensation signal and radiates audio indicative thereof to the listening position. The transfer function characteristics from the input of the bass management system to the listening position approximately matches a desired transfer function. | 04-02-2009 |
20100002892 | Active noise reduction system and active noise reduction method - As optimal candidate as a control signal (y*) for generating a control sound suppressing noise from a speaker is selected from among a plurality of control signal candidates (y | 01-07-2010 |
20100027805 | Transfer function estimating device, noise suppressing apparatus and transfer function estimating method - A transfer function estimating device for estimating a transfer function of a sound, includes: a sound receiving module receiving a sound from a given sound source and converting the sound into a tone signal; a storage module storing first transfer functions of the sound propagating from the given sound source to the sound receiving module and transformation coefficients for converting the first transfer functions into given second transfer functions so as to associate with each other; a reference tone signal acquiring module acquiring a reference tone signal of the sound source; an acquiring module acquiring a transfer function of the sound received by the sound receiving module on the basis of the tone signal and the reference tone signal; a specifying module acquiring a cross-correlation value between the transfer function acquired by the acquiring module and each of the first transfer functions stored in the storage module. | 02-04-2010 |
20110293106 | Signal Processing Circuit for the Generation of a Loudspeaker Signal and Signal-Processing Method - A signal-processing circuit for the generation of a loudspeaker signal comprises an input for the feeding of a digital input signal and a digital equalizer filter that is coupled with the input and has at least one first recursive filter that is defined by a first adjustable set of coefficients. An amplification device coupled with the equalizer filter is designed to generate the loudspeaker signal as a function of the filtered input signal and to output on an output terminal. A current measurement device is designed to output a digital measurement signal that represents a current of the loudspeaker signal. A digital filter block is designed to generate, through filtering, an estimate signal as a function of the measurement signal. For this purpose, the filter block has at least one second recursive filter that is defined by a second adjustable set of coefficients. A matching block is designed to determine a new set of coefficients as a function of the measurement signal, the estimate signal, and the filtered input signal and to use the newly determined coefficients in the first and second adjustable set of coefficients such that the resulting transfer functions of the at least one first and the at least one second filters are inverse relative to each other. | 12-01-2011 |
20120106750 | AUDIO DRIVER SYSTEM AND METHOD - A system and apparatus for constructing a displacement model across a frequency range for a loudspeaker is disclosed. The resultant displacement model is centered around the distortion point. Once a distortion model is constructed it can be incorporated into an audio driver to prevent distortion by incorporating the model and a distortion compensation unit with a conventional audio driver. Various topologies can be used to incorporate a distortion model and distortion compensation unit into an audio driver. Furthermore, a wide variety of distortion compensation techniques can be employed to avoid distortion in such an audio driver. | 05-03-2012 |
20120155669 | OPEN-WORKED ACOUSTIC BARRIER FOR HYBRID ACTIVE/PASSIVE NOISE TREATMENT - The invention relates to a method and a device for passive and active acoustic reduction, including m electro-acoustic bars ( | 06-21-2012 |
20120308029 | ADAPTIVE FILTERING SYSTEM - An audio system with at least one audio channel may include a digital audio processor in which at least one digital filter is implemented for each channel. The digital filter of each channel may include: an analysis filter bank configured to receive a broad-band input audio signal and divide the input audio signal into a plurality of sub-bands, a sub-band filter for each sub-band. and a synthesis filter bank configured to receive the filtered sub-band signals and combine them for providing a broad-band output audio signal. A delay is associated with each sub-band signal, the delay of one of the sub-band signals being applied to the broad-band input audio signal upstream of the analysis filter bank and the residual delays being applied to the remaining sub-band signals downstream of the analysis filter bank. | 12-06-2012 |
20130064383 | INFORMATION SIGNAL REPRESENTATION USING LAPPED TRANSFORM - An information signal reconstructor is configured to reconstruct, using aliasing cancellation, an information signal from a lapped transform representation of the information signal including, for each of consecutive, overlapping regions of the information signal, a transform of a windowed version of the respective region, wherein the information signal reconstructor is configured to reconstruct the information signal at a sample rate which changes at a border between a preceding region and a succeeding region of the information signal. | 03-14-2013 |
20130259253 | CONTROLLERS FOR ACTIVE NOISE CONTROL SYSTEMS - A method for obtaining coefficients for a non-adaptive controller for use in an active noise control system, the method comprising capturing experimental data from a target system to characterise the plant of the target system; and implementing an adaptive algorithm to compute the coefficients in dependence on the experimental data. | 10-03-2013 |
20140098968 | NOISE SUPPRESSION DEVICE - Disclosed is a noise suppression device including an input signal analyzer | 04-10-2014 |
20160005390 | METHOD FOR ACTIVE NARROW-BAND ACOUSTIC CONTROL WITH VARIABLE TRANSFER FUNCTION(S), AND CORRESPONDING SYSTEM - An active acoustic control method for attenuating disturbing narrow-band noise with at least one counter-noise loudspeaker and at least one error microphone in a space forming a material electroacoustic system, the method implementing, in a computing element, a control law with an internal model and disturbance observer with a model of the electroacoustic system, previously obtained by an identification method. The current configuration of the electroacoustic system can vary over time, a nominal configuration of the electroacoustic system is previously determined, a corresponding nominal model M | 01-07-2016 |
20160063987 | UNMANNED AERIAL VEHICLE (UAV) FOR COLLECTING AUDIO DATA - A UAV is provided to cancel background noise from audio data collected by the UAV. The UAV is provided with one or more background microphones in a proximity of one or more background noise-producing components. The UAV is also provided with one or more audio source collecting microphones. The audio data collected by the background microphones may be used to reduce or cancel interfering background noise from the audio signal detected by the audio source collecting microphone. The target audio may be captured or recorded with little or no background noise. | 03-03-2016 |