Patent application number | Description | Published |
20100260344 | Method and Arrangement for Echo Cancellation of Voice Signals - A method and arrangement for cancelling echoes in a communication terminal ( | 10-14-2010 |
20100274561 | Noise Suppression Method and Apparatus - The present invention relates to a method and apparatus of a digital filter for noise suppression of a signal representing an acoustic recording. The method comprises determining a desired frequency response (H(ω)) of the digital filter; and generating a noise suppression filter based on the desired frequency response. The desired frequency response is determined in a manner so that the desired frequency response does not exceed a maximum level, wherein the maximum level is determined in response to the signal to be filtered. | 10-28-2010 |
20110137646 | Noise Suppression Method and Apparatus - The present invention relates to a method and a filter design apparatus for designing a digital filter arrangement for noise suppression of a signal representing an acoustic recording. The method comprises determining a desired frequency response of the digital filter arrangement. The method is characterised by including a combination of a high pass filter and a noise suppression filter in the filter arrangement. The combination of the high pass filter and the noise suppression filter is selected based on the determined desired frequency response. | 06-09-2011 |
20130044872 | ECHO CANCELLER AND A METHOD THEREOF - The present invention relates to an echo canceller ( | 02-21-2013 |
20130272540 | NOISE SUPPRESSING METHOD AND A NOISE SUPPRESSOR FOR APPLYING THE NOISE SUPPRESSING METHOD - A method for suppressing noise of a first signal captured via a primary microphone is provided. A primary and a reference microphone are arranged on a communication device to capture noise and intermittent speech. A determination is made whether the first signal comprises non-stationary signal components or substantially stationary noise, and whether the first signal comprises substantially far-field noise in case it was determined that it comprises non-stationary signal components. A noise power spectrum estimate of the first signal is updated with a stationary noise power spectrum estimate if the first signal is considered to comprise substantially stationary noise or a far-field noise power spectrum estimate if the first signal is considered to comprise substantially far-field noise. A frequency response is computed on the basis of the estimated noise power spectrum. Noise from the first signal is suppressed by applying the frequency response on the first signal. | 10-17-2013 |
20130287216 | ESTIMATION AND SUPPRESSION OF HARMONIC LOUDSPEAKER NONLINEARITIES - A harmonic echo power estimator estimates power of echo generated by harmonic loudspeaker nonlinearities in a user equipment having an echo path between a loudspeaker input and a microphone output. The estimator includes a frequency band mapper that maps each frequency band in a set of loudspeaker output signal frequency bands into a corresponding array of loudspeaker input signal frequency bands, where each frequency band in the set is mapped into several frequency bands in the corresponding array. A power estimator determines a power estimate of each input signal in each array of frequency bands. A power estimate combiner combines determined power estimates in each array of frequency bands into a corresponding estimate of loudspeaker input power generating harmonic loudspeaker nonlinearities. A power estimate transformer transforms the estimates of loudspeaker input power across the echo path into power estimates of the echo generated by the harmonic loudspeaker nonlinearities. | 10-31-2013 |
20140177858 | ECHO SUPPRESSION - Method, user device and computer program product for suppressing echo. An audio signal is output from a speaker. A microphone receives an audio signal, wherein the received audio signal includes an echo resulting from said outputted audio signal. A Finite Impulse Response filter estimate ĥ(t) is dynamically adapted in the time domain based on the outputted audio signal and the received audio signal to model an echo path h(t) of the echo in the received audio signal. At least one power response is determined from the filter estimate ĥ(t) and used to estimate the echo power of the echo in the received audio signal. The estimated echo power is used to apply echo suppression to the received audio signal, thereby suppressing the echo in the received audio signal. | 06-26-2014 |
20140177859 | ECHO SUPPRESSION - Method, user device and computer program product for suppressing echo. An audio signal is outputted from a speaker. A microphone receives an audio signal which includes echo resulting from said outputted audio signal. An echo path of the echo is modelled using a plurality of models. A first of the models is a FIR based model and a second of the models is different to the first model. The first model is used to determine a first model estimate of the echo power of a first component of the echo. The second model is used to determine a second model estimate of the echo power of a second component of the echo. The first and second model estimates of the echo power are combined. The combined estimate of the echo power is used to apply echo suppression to the received audio signal, thereby suppressing the echo. | 06-26-2014 |
20140334631 | NOISE REDUCTION - A method of reducing noise in an acoustic system, the method comprising at a first user terminal: receiving an audio signal from at least one further user terminal over a network; executing a communication client on a processing unit, the client configured so as when executed to: supply the audio signal to an audio signal processing module of the first user terminal, wherein the processing module processes the audio signal, whereby a level of gain is applied to the audio signal, and outputs a processed audio signal to a speaker; estimate a noise level of the audio signal and the processed audio signal and estimate the gain applied by the processing module taking into account both the noise level estimates; selectively apply a system gain reduction step to at least one of the audio signal and an audio signal received via a microphone, based on at least the estimated gain. | 11-13-2014 |
20140355752 | ECHO CANCELLATION - A method of echo cancellation in an acoustic system, comprising a first user device and at least one further user device, the method comprising, at the first user device: detecting an audio signal received from the at least one further user device over a communications network; supplying the audio signal when received to an audio signal processing module of the first user device, wherein the audio signal processing module processes the audio signal and outputs a processed audio signal to audio output means of the first user device; and controlling an echo cancellation process for cancelling echo from an audio signal received via audio input means of the first user device based on a loopback signal provided by the processed audio signal and selectively based on the received audio signal when detected. | 12-04-2014 |
20140357323 | ECHO REMOVAL - Echo removal techniques are described. An echo path of the echo in a received audio signal is modelled using a first model to determine a first model estimate of the echo. The first model estimate is used to determine a first performance value according to a performance metric. The first performance value is compared with a threshold value. It is determined if the echo path can be deemed linear based on the comparison. If so, the first model estimate of the echo is used to remove the echo in the received audio signal. Otherwise, the echo path of the echo is switched to be modelled using a second model to determine a second model estimate of the echo, and the second model estimate of the echo is used to remove the echo in the received audio signal. | 12-04-2014 |
20140357324 | ECHO REMOVAL - Echo removal techniques are described. As part of the echo removal, an adaptive model estimate of the echo in a received audio signal is determined using an adaptive model based on an outputted audio signal and the received audio signal. The adaptive model executes an algorithm comprising a convergence parameter to determine filter coefficients and uses said filter coefficients to filter the outputted audio signal to determine the adaptive model estimate of the echo. An accuracy value of the adaptive model is determined according to an echo return loss enhancement metric. The convergence parameter is updated based on the accuracy value. The adaptive model estimate of the echo is used to remove the echo in the received audio signal. | 12-04-2014 |
20140357325 | ECHO REMOVAL - Echo removal techniques are described. As part of the echo removal, a first model estimate of the echo in the received audio signal is determined using a first model and a second model estimate of the echo is determined using a second model. A first accuracy value of the first model is determined according to a model accuracy measure, and a second accuracy value of the second model is determined according to the model accuracy measure. It is then determined if the first model is more accurate than the second model based on a comparison of the first accuracy value and the second accuracy value and the second model is selectively updated based on said comparison. Echo removal is applied to the received audio signal using only the second model estimate of the echo. | 12-04-2014 |
20140357326 | ECHO SUPPRESSION - An echo path of the echo in a received audio signal is modelled using an adaptive model to determine an adaptive model estimate of the echo. The adaptive model estimate is used to determine an estimate of the echo power of the echo in the received audio signal. The power of the received audio signal is determined. The estimate of the echo power and the determined power of the received audio signal are used to determine echo suppression gains. Temporal smoothing is applied to one or more of the echo suppression gains and the one or more smoothed echo suppression gains are used to apply echo suppression to the received audio signal, thereby suppressing the echo in the received audio signal, wherein the amount of smoothing applied to the echo suppression gains is varied according to a non-decreasing function of the frequency of the received audio signal. | 12-04-2014 |