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Noise Cancellation

Jing Mi, H Steven Colburn
Spatially separating speech maskers from target speech often leads to a large intelligibility improvement. Modeling this phenomenon has long been of interest to binaural-hearing researchers for uncovering brain mechanisms and for improving signal-processing algorithms in hearing-assistive devices. Much of the previous binaural modeling work focused on the unmasking enabled by binaural cues at the periphery, and little quantitative modeling has been directed toward the grouping or source-separation benefits of binaural processing...
October 3, 2016: Trends in Hearing
Mark A Georgeson, Andrew J Schofield
Combination of signals from the two eyes is the gateway to stereo vision. To gain insight into binocular signal processing, we studied binocular summation for luminance-modulated gratings (L or LM) and contrast-modulated gratings (CM). We measured 2AFC detection thresholds for a signal grating (0.75c/deg, 216ms) shown to one eye, both eyes, or both eyes out-of-phase. For LM and CM, the carrier noise was in both eyes, even when the signal was monocular. Mean binocular thresholds for luminance gratings (L) were 5...
October 14, 2016: Vision Research
Iman Ghodratitoostani, Yossi Zana, Alexandre C B Delbem, Siamak S Sani, Hamed Ekhtiari, Tanit G Sanchez
Subjective tinnitus is the conscious (attended) awareness perception of sound in the absence of an external source and can be classified as an auditory phantom perception. Earlier literature establishes three distinct states of conscious perception as unattended, attended, and attended awareness conscious perception. The current tinnitus development models depend on the role of external events congruently paired with the causal physical events that precipitate the phantom perception. We propose a novel Neurofunctional Tinnitus Model to indicate that the conscious (attended) awareness perception of phantom sound is essential in activating the cognitive-emotional value...
2016: Frontiers in Neuroscience
Fintan Costello, Paul Watts
A common view in current psychology is that people estimate probabilities using various 'heuristics' or rules of thumb that do not follow the normative rules of probability theory. We present a model where people estimate conditional probabilities such as P(A|B) (the probability of A given that B has occurred) by a process that follows standard frequentist probability theory but is subject to random noise. This model accounts for various results from previous studies of conditional probability judgment. This model predicts that people's conditional probability judgments will agree with a series of fundamental identities in probability theory whose form cancels the effect of noise, while deviating from probability theory in other expressions whose form does not allow such cancellation...
September 2016: Cognitive Psychology
Shigeo Nagano, Motohiro Kumagai, Ying Li, Tetsuya Ido, Shoken Ishii, Kohei Mizutani, Makoto Aoki, Ryohei Otsuka, Yuko Hanado
We disseminated an ultra-broadband optical frequency reference based on a femtosecond (fs)-laser optical comb through a kilometer-scale fiber link. Its spectrum ranged from 1160 nm to 2180 nm without additional fs-laser combs at the end of the link. By employing a fiber-induced phase noise cancellation technique, the linewidth and fractional frequency instability attained for all disseminated comb modes were of order 1 Hz and 10<sup>-18</sup> in a 5000 s averaging time. The ultra-broad optical frequency reference, for which absolute frequency is traceable to Japan Standard Time, was applied in the frequency stabilization of an injection-seeded Q-switched 2051 nm pulse laser for a coherent light detection and ranging LIDAR system...
August 22, 2016: Optics Express
D Panigrahy, P K Sahu
Electrocardiogram (ECG) signal gives a lot of information on the physiology of heart. In reality, noise from various sources interfere with the ECG signal. To get the correct information on physiology of the heart, noise cancellation of the ECG signal is required. In this paper, the effectiveness of extended Kalman smoother (EKS) with the differential evolution (DE) technique for noise cancellation of the ECG signal is investigated. DE is used as an automatic parameter selection method for the selection of ten optimized components of the ECG signal, and those are used to create the ECG signal according to the real ECG signal...
September 2016: Australasian Physical & Engineering Sciences in Medicine
Alexandre Chabot-Leclerc, Ewen N MacDonald, Torsten Dau
This study proposes a binaural extension to the multi-resolution speech-based envelope power spectrum model (mr-sEPSM) [Jørgensen, Ewert, and Dau (2013). J. Acoust. Soc. Am. 134, 436-446]. It consists of a combination of better-ear (BE) and binaural unmasking processes, implemented as two monaural realizations of the mr-sEPSM combined with a short-term equalization-cancellation process, and uses the signal-to-noise ratio in the envelope domain (SNRenv) as the decision metric. The model requires only two parameters to be fitted per speech material and does not require an explicit frequency weighting...
July 2016: Journal of the Acoustical Society of America
Huadan Zheng, Lei Dong, Ying Ma, Hongpeng Wu, Xiaoli Liu, Xukun Yin, Lei Zhang, Weiguang Ma, Wangbao Yin, Liantuan Xiao, Suotang Jia
A sub-ppb-level nitrogen dioxide (NO<sub>2</sub>) QEPAS sensor is developed by use of a cost-effective wide stripe laser diode (LD) emitting at 450 nm and a novel background noise suppression method called scattered light modulation cancellation method (SL-MOCAM). The SL-MOCAM is a variant of modulation spectroscopy using two light sources: excitation and balance light sources. The background noise caused by the stray light of the excitation light sources can be eliminated by exposing the QEPAS spectrophone to the modulated balance light...
May 16, 2016: Optics Express
Terry G McRae, Silvie Ngo, Timothy T-Y Lam, David E McClelland, Jong H Chow, Daniel A Shaddock, Malcolm B Gray
This experiment uses digital interferometry to reduce polarisation noise from a fiber interferometer to the level of double Rayleigh backscatter making precision fiber metrology systems robust for remote field applications. This is achieved with a measurement of the Jones matrix with interferometric sensitivity in real time, limited only by fibre length and processing bandwidth. This new approach leads to potentially new metrology applications and the ability to do ellipsometry without polarisation elements in the output field...
May 16, 2016: Optics Express
Daisaku Hiraoka, Ryota Aono, Shin-Ichiro Hanada, Eiichi Okumura, Takeo Kishimoto
Extracellular ligands control biological phenomena. Cells distinguish physiological stimuli from weak noise stimuli by establishing a ligand-concentration threshold. Hormonal control of the meiotic G2/M transition in oocytes is essential for reproduction. However, the mechanism for threshold establishment is unclear. In starfish oocytes, maturation-inducing hormones activate the PI3K-Akt pathway through the Gβγ complex of heterotrimeric G-proteins. Akt directly phosphorylates both Cdc25 phosphatase and Myt1 kinase, resulting in activation of cyclin-B-Cdk1, which then induces meiotic G2/M transition...
August 15, 2016: Journal of Cell Science
Madhavi Mallam, K Chandra Bhutan Rao
In this paper, a new model for adaptive artifact cancelation in impedance cardiography (ICG) signals is presented. It is a hybrid model based on wavelet decomposition and an adaptive filter. A novel feature of this model is the implementation of reference-free adaptive artifact cancellers (AAC). For this implementation, the reference signal is constructed using a wavelet transformation. During critical conditions the filter weights may be negative and cause an imbalance in the convergence. To overcome this problem, we introduce non-negative adaptive algorithms in the proposed artifact canceller...
2016: SpringerPlus
Shin Hye Kim, Ji Hye Jang, Sang-Yeon Lee, Jae Joon Han, Ja-Won Koo, Sven Vanneste, Dirk De Ridder, Jae-Jin Song
Although tinnitus retraining therapy (TRT) is efficacious in most patients, the exact mechanism is unclear and no predictor of improvement is available. We correlated the extent of improvement with pre-TRT quantitative electroencephalography (qEEG) findings to identify neural predictors of improvement after TRT. Thirty-two patients with debilitating tinnitus were prospectively enrolled, and qEEG data were recorded before their initial TRT sessions. Three months later, these qEEG findings were correlated with the percentage improvements in the Tinnitus Handicap Inventory (THI) scores, and numeric rating scale (NRS) scores of tinnitus loudness and tinnitus perception...
2016: Scientific Reports
Zhong Ren, Xiaojing Yang
X-ray crystallography promises direct insights into electron-density changes that lead to and arise from structural changes such as electron and proton transfer and the formation, rupture and isomerization of chemical bonds. The ultrashort pulses of hard X-rays produced by free-electron lasers present an exciting opportunity for capturing ultrafast structural events in biological macromolecules within femtoseconds after photoexcitation. However, shot-to-shot fluctuations, which are inherent to the very process of self-amplified spontaneous emission (SASE) that generates the ultrashort X-ray pulses, are a major source of noise that may conceal signals from structural changes...
July 2016: Acta Crystallographica. Section D, Structural Biology
Chung Ming Leung, Feifei Wang, Ya Wang
A novel magnetoelectric (ME) laminated composite structure is proposed in this work, aiming to provide a good self-vibration cancellation performance under the magnetic field detection environment. The proposed structure consists of two Terfenol-D magnetostrictive alloy plates which are revised and length-magnetized by two NdFeB magnets bonded on the top surface of a thickness-polarized Pb(Zr, Ti)O3 (PZT) ceramic plate with separate electrodes. Experiments have shown that great vibration suppression up to 44 dB under harmonic disturbance was observed...
June 2016: Review of Scientific Instruments
Yushun Liu, Wenjun Zhou, Pengfei Li, Shuai Yang, Yan Tian
Due to electromagnetic interference in power substations, the partial discharge (PD) signals detected by ultrahigh frequency (UHF) antenna sensors often contain various background noises, which may hamper high voltage apparatus fault diagnosis and localization. This paper proposes a novel de-noising method based on the generalized S-transform and module time-frequency matrix to suppress noise in UHF PD signals. The sub-matrix maximum module value method is employed to calculate the frequencies and amplitudes of periodic narrowband noise, and suppress noise through the reverse phase cancellation technique...
2016: Sensors
Scott S Hsieh, Norbert J Pelc
Energy-discriminating, photon-counting (EDPC) detectors are attractive for their potential for improved detective quantum efficiency and for their spectral imaging capabilities. However, at high count rates, counts are lost, the detected spectrum is distorted, and the advantages of EDPC detectors disappear. Existing EDPC detectors identify counts by analyzing the signal with a bank of comparators. We explored alternative methods for pulse detection for multibin EDPC detectors that could improve performance at high count rates...
April 2016: Journal of Medical Imaging
Adriano Contillo, Giovanni Di Domenico, Paolo Cardarelli, Mauro Gambaccini, Angelo Taibi
PURPOSE: Dual-energy image subtraction represents a useful tool to improve the detectability of small lesions, especially in dense breasts. A feature it shares with all x-ray imaging techniques is the appearance of fluctuations in the texture of the background, which can obscure the visibility of interesting details. The aim of the work is to investigate the main noise sources, in order to create a better performing subtraction mechanism. In particular, the structural noise cancellation was achieved by means of a suitable extension of the dual-energy algorithm...
June 2016: Medical Physics
Gavin M Bidelman, Chhayakanta Patro
When noise obstructs portions of target sounds the auditory system fills in missing information, a phenomenon known as auditory restoration or induction. Previous work in animal models demonstrates that neurons in primary auditory cortex (A1) are capable of restoring occluded target signals suggesting that early auditory cortex is capable of inducing continuity in discontinuous signals (i.e., endogenous restoration). Current consensus is that the neural correlates of auditory induction and perceptual restoration emerge no earlier than A1...
September 1, 2016: Brain Research
Minho Choi, Jae Jin Jeong, Seung Hun Kim, Sang Woo Kim
Non-intrusive electrocardiogram (ECG) monitoring has many advantages: easy to measure and apply in daily life. However, motion noise in the measured signal is the major problem of non-intrusive measurement. This paper proposes a method to reduce the noise and to detect the R peaks of ECG in a stable manner in a sitting arrangement using non-intrusive sensors. The method utilizes two capacitive ECG sensors (cECGs) to measure ECG, and another two cECGs located adjacent to the sensors for ECG are added to obtain the information on motion...
2016: Sensors
Kai Xie, Yan Liu, XiaoPing Li, Lixin Guo, Hanlu Zhang
The bandwidth and low noise characteristics are often contradictory in ultra-low current amplifier, because an inevitable parasitic capacitance is paralleled with the high value feedback resistor. In order to expand the amplifier's bandwidth, a novel approach was proposed by introducing an artificial negative capacitor to cancel the parasitic capacitance. The theory of the negative capacitance and the performance of the improved amplifier circuit with the negative capacitor are presented in this manuscript...
April 2016: Review of Scientific Instruments
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