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Patent

Normalized frequency domain LMS adaptive filter

TLDR
In this article, a normalized frequency domain Least Means Square filter is proposed, where the power estimate is incorporated directly into the filter algorithm as a data-dependent, time-varying stochastic feedback coefficient.
Abstract
A normalized frequency domain Least Means Square filter. The feedback coefficient for each frequency bin is adjusted separately in the filter by use of an input power estimate. The power estimate is incorporated directly into the filter algorithm as a data-dependent, time-varying stochastic feedback coefficient. The filter is particularly useful in applications in which the input signal has large spectral variations, which could lead to filter instabilities in some frequency bins if a single feedback coefficient were employed in all frequency bins.

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Citations
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Patent

Active control of noise and vibration

TL;DR: An active system for controlling vibration or sound includes a method for limiting the output gain G from a gradient descent algorithm, such as an LMS algorithm, according to the relationship ##EQU1## and reducing one of first and second filter weights W1 and W0 such that the output canceling signal is never saturated.
PatentDOI

Hearing aid device incorporating signal processing techniques

TL;DR: In this paper, a hearing compensation system for the hearing impaired comprises a plurality of bandpass filters having an input connected to an input transducer and each bandpass filter having an output connected to the input of one of a multiplicative AGC circuits.
PatentDOI

Feedback cancellation improvements

TL;DR: In this article, a cascade of two filters along with a short bulk delay is used to adjust the filter response to make the most effective use of the limited number of filter coefficients.
Patent

Periodic signal enhancement system

TL;DR: In this paper, the authors proposed a signal enhancement system that includes delay logic, a partitioned adaptive filter, and signal reinforcement logic to improve the understandability of speech or other audio signals.
PatentDOI

Subband acoustic feedback cancellation in hearing aids

TL;DR: In this paper, a cascade of two narrow-band filters Ai(Z) and Bi(Zng) with a fixed delay is proposed to represent the feedback path in each subband.
References
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Journal ArticleDOI

Adaptive filtering in the frequency domain

TL;DR: Adaptive filtering in the frequency domain can be accomplished by Fourier transformation of the input signal and independent weighting of the contents of each frequency bin this article, which performs similarly to a conventional adaptive transversal filter but promises a significant reduction in computation when the number of weights equals or exceeds 16.
Journal ArticleDOI

Block implementation of adaptive digital filters

TL;DR: A block adaptive filtering procedure in which the filter coefficients are adjusted once per each output block in accordance with a generalized least mean-square (LMS) algorithm shows that it permits fast implementations while maintaining performance equivalent to that of the widely used LMS adaptive filter.
PatentDOI

Adaptive noise suppressor

TL;DR: An adaptive noise suppressor for providing noise filtered signals as discussed by the authors employs a vector gain μ for the weights of the filter wherein the vector μ is selected for each frequency bin to be inversely proportional to the power spectrum.
Patent

Two-input crosstalk-resistant adaptive noise canceller

TL;DR: In this paper, a two-input crosstalk-resistant adaptive noise canceller with first and second-summer means was proposed, where the first summer means provides a canceller output signal which is the difference between the primary input signal and the first adaptive filter output signal.