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Noise measurement

About: Noise measurement is a research topic. Over the lifetime, 19776 publications have been published within this topic receiving 308180 citations.


Papers
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Journal ArticleDOI
TL;DR: A more general expression of the post-filter estimation is developed based on an assumed knowledge of the complex coherence of the noise field that can be used to construct a more appropriate post- filter in a variety of different noise fields.
Abstract: This paper introduces a novel technique for estimating the signal power spectral density to be used in the transfer function of a microphone array post-filter. The technique is a generalization of the existing Zelinski post-filter, which uses the auto- and cross-spectral densities of the array inputs to estimate the signal and noise spectral densities. The Zelinski technique, however, assumes zero cross-correlation between the noise on different sensors. This assumption is inaccurate, particularly at low frequencies and for arrays with closely spaced sensors, and thus the corresponding post-filter is suboptimal in realistic noise conditions. In this paper, a more general expression of the post-filter estimation is developed based on an assumed knowledge of the complex coherence of the noise field. This general expression can be used to construct a more appropriate post-filter in a variety of different noise fields. In experiments using real noise recordings from a computer office, the modified post-filter results in significant improvement in terms of objective speech quality measures and speech recognition performance using a diffuse noise model.

316 citations

Journal ArticleDOI
TL;DR: Boundedness and ultimate boundedness of the closed-loop system under switched-gain output feedback is argued and a high-gain observer that switches between two gain values is proposed.

315 citations

Journal ArticleDOI
TL;DR: A new fuzzy filter is presented for the noise reduction of images corrupted with additive noise, based on fuzzy rules which make use of membership functions.
Abstract: A new fuzzy filter is presented for the noise reduction of images corrupted with additive noise. The filter consists of two stages. The first stage computes a fuzzy derivative for eight different directions. The second stage uses these fuzzy derivatives to perform fuzzy smoothing by weighting the contributions of neighboring pixel values. Both stages are based on fuzzy rules which make use of membership functions. The filter can be applied iteratively to effectively reduce heavy noise. In particular, the shape of the membership functions is adapted according to the remaining noise level after each iteration, making use of the distribution of the homogeneity in the image. A statistical model for the noise distribution can be incorporated to relate the homogeneity to the adaptation scheme of the membership functions. Experimental results are obtained to show the feasibility of the proposed approach. These results are also compared to other filters by numerical measures and visual inspection.

314 citations

Journal ArticleDOI
TL;DR: In this article, a low-noise high-frequency transresistance amplifier was used to accurately measure broadband noise in MOSFETs with small widths and submicrometer channel lengths.
Abstract: A low-noise high-frequency transresistance amplifier has been used to accurately measure broad-band noise in MOSFET's with small widths and submicrometer channel lengths The technique allows noise characterization up to frequencies of 100 MHz of the small devices available as process test arrays from different fabrication lines The noise in the different portions of the I-V characteristics of submicrometer MOSFET's has been characterized and shown to be greater by factors of 2 to 4 than the noise expected from long-channel noise theory

310 citations

Journal ArticleDOI
01 Aug 1969
TL;DR: In this paper, a novel noise measurement technique is outlined which results in data that directly gives the noise parameters of the test device when processed by a simple computer program, which can be used to estimate the noise of a test device.
Abstract: A novel noise measurement technique is outlined which results in data that directly give the noise parameters of the test device when processed by a simple computer program.

310 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202377
2022162
2021495
2020525
2019489
2018755