Signal to Noise: A Computer-Based Artist's Book

Purpose The goal of this study was to determine whether hearing aids in combination with computer-based auditory training improve audiovisual (AV) performance compared with the use of hearing aids alone. Method Twenty-four participants were randomized into an experimental group (hearing aids plus ReadMyQuips [RMQ] training) and a control group (hearing aids only). The Multimodal Lexical Sentence Test for Adults (Kirk et al., 2012) was used to measure auditory-only (AO) and AV speech perception performance at three signal-to-noise ratios (SNRs). Participants were tested at the time of hearing aid fitting (pretest), after 4 weeks of hearing aid use (posttest I), and again after 4 weeks of RMQ training (posttest II). Results Results did not reveal an effect of training. As expected, interactions were found between (a) modality (AO vs. AV) and SNR and (b) test (pretest vs. posttests) and SNR. Conclusion Data do not show a significant effect of RMQ training on AO or AV performance as measured using the Multimodal Lexical Sentence Test for Adults.

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A computer-based method to increase the signal-to-noise ratio of negative-ion currents in double-charge-transfer spectroscopy

Rapid Communications in Mass Spectrometry ◽

10.1002/rcm.1290091508 ◽

1995 ◽

Vol 9 (15) ◽

pp. 1502-1506 ◽

Cited By ~ 1

Author(s):

Mark A. Bayliss ◽

Frank M. Harris ◽

David E. Parry ◽

Stephen Evans

Keyword(s):

Charge Transfer ◽

Signal To Noise Ratio ◽

Negative Ion ◽

Ion Currents ◽

Signal To Noise ◽

Computer Based ◽

Noise Ratio ◽

Double Charge

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Key elements of total seismic field design using Mathematica—A tutorial

Geophysics ◽

10.1190/1.1500362 ◽

2002 ◽

Vol 67 (4) ◽

pp. 1020-1027 ◽

Cited By ~ 3

Author(s):

Ninos Benyamin

Keyword(s):

Dynamic Range ◽

Signal To Noise Ratio ◽

Computer Language ◽

Signal To Noise ◽

Seismic Surveys ◽

System Noise ◽

Effective Dynamic ◽

Seismic Recording ◽

Computer Based ◽

Receiver Arrays

This tutorial reviews the basics of total seismic field design and provides personal‐computer–based computer language codes that can readily be used, with some modification, to design seismic surveys in the field. The finite effective dynamic range of seismic recording systems together with an overlap of signal and noise spectra suggest that a certain amount of prefiltering is needed during the acquisition phase to insure that a weak signal does not fall below the system noise, which would render the signal useless. The key elements of a total seismic field design are reviewed and, by way of a hypothetical 3‐D field example, their implementation is illustrated. The recommended solution consists of parameters for spread geometry that will record maximum geologic dips without aliasing, and shot and receiver arrays that optimize the signal‐to‐noise ratio.

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Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068291 ◽

1970 ◽

Vol 28 ◽

pp. 260-261

Author(s):

Robert M. Glaeser

Keyword(s):

High Resolution ◽

Particle Flux ◽

Unit Area ◽

Signal To Noise ◽

Resolution Image ◽

High Resolution Image ◽

Pass Through ◽

Counting Statistics ◽

The Relationship ◽

Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

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Determination of the Best Emulsion for the Microscopy of Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100096886 ◽

1981 ◽

Vol 39 ◽

pp. 32-33

Author(s):

David A. Grano ◽

Kenneth H. Downing

Keyword(s):

Spatial Frequency ◽

Information Transfer ◽

Signal To Noise Ratio ◽

Experimental Situation ◽

Photographic Emulsion ◽

Modulation Transfer ◽

Signal To Noise ◽

Frequency Space ◽

Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

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Experiments in Bright-Field Imaging with Hollow-Cone Illumination

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097703 ◽

1981 ◽

Vol 39 ◽

pp. 226-227

Author(s):

W. Kunath ◽

K. Weiss ◽

E. Zeitler

Keyword(s):

Signal To Noise Ratio ◽

Carbon Support ◽

Electronic System ◽

Optic Axis ◽

Hollow Cone ◽

Signal To Noise ◽

Bright Field ◽

Noise Ratio ◽

Single Field ◽

Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

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Cell morphology, volume, and surface area determinations from multilevel contouring within HVEM micrographs of serial sections and whole-cell mounts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100127426 ◽

1987 ◽

Vol 45 ◽

pp. 588-589

Author(s):

M. Marko ◽

A. Leith ◽

D. Parsons

Keyword(s):

Surface Area ◽

Electron Micrographs ◽

Cell Morphology ◽

Individual Variation ◽

Serial Section ◽

Stereo Pair ◽

Complex Structures ◽

Serial Sections ◽

Surface Areas ◽

Computer Based

The use of serial sections and computer-based 3-D reconstruction techniques affords an opportunity not only to visualize the shape and distribution of the structures being studied, but also to determine their volumes and surface areas. Up until now, this has been done using serial ultrathin sections.The serial-section approach differs from the stereo logical methods of Weibel in that it is based on the Information from a set of single, complete cells (or organelles) rather than on a random 2-dimensional sampling of a population of cells. Because of this, it can more easily provide absolute values of volume and surface area, especially for highly-complex structures. It also allows study of individual variation among the cells, and study of structures which occur only infrequently.We have developed a system for 3-D reconstruction of objects from stereo-pair electron micrographs of thick specimens.

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Ultra-spatially resolved synchrotron powered FT-IR microspectroscopy of individual cells of biological material

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140798 ◽

1995 ◽

Vol 53 ◽

pp. 884-885

Author(s):

David L. Wetzel ◽

John A. Reffner ◽

Gwyn P. Williams

Keyword(s):

Thermal Noise ◽

Spot Size ◽

Acquisition Time ◽

Thermal Source ◽

Signal To Noise ◽

Spatially Resolved ◽

Good Spatial Resolution ◽

Small Spot ◽

Ft Ir ◽

Ir Microspectroscopy

Synchrotron radiation is 100 to 1000 times brighter than a thermal source such as a globar. It is not accompanied with thermal noise and it is highly directional and nondivergent. For these reasons, it is well suited for ultra-spatially resolved FT-IR microspectroscopy. In efforts to attain good spatial resolution in FT-IR microspectroscopy with a thermal source, a considerable fraction of the infrared beam focused onto the specimen is lost when projected remote apertures are used to achieve a small spot size. This is the case because of divergence in the beam from that source. Also the brightness is limited and it is necessary to compromise on the signal-to-noise or to expect a long acquisition time from coadding many scans. A synchrotron powered FT-IR Microspectrometer does not suffer from this effect. Since most of the unaperatured beam’s energy makes it through even a 12 × 12 μm aperture, that is a starting place for aperture dimension reduction.

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Resolution assessment from spectral signal-to-noise ratios

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128043 ◽

1987 ◽

Vol 45 ◽

pp. 746-747

Author(s):

M. Unser ◽

B.L. Trus ◽

A.C. Steven

Keyword(s):

Electron Microscopy ◽

Limiting Factor ◽

Biological Macromolecules ◽

Signal To Noise ◽

Differential Phase ◽

Traditional Measure ◽

Spectral Signal ◽

Two Measures ◽

Diffraction Patterns ◽

Averaging Techniques

Since the resolution-limiting factor in electron microscopy of biological macromolecules is not instrumental, but is rather the preservation of structure, operational definitions of resolution have to be based on the mutual consistency of a set of like images. The traditional measure of resolution for crystalline specimens in terms of the extent of periodic reflections in their diffraction patterns is such a criterion. With the advent of correlation averaging techniques for lattice rectification and the analysis of non-crystalline specimens, a more general - and desirably, closely compatible - resolution criterion is needed. Two measures of resolution for correlation-averaged images have been described, namely the differential phase residual (DPR) and the Fourier ring correlation (FRC). However, the values that they give for resolution often differ substantially. Furthermore, neither method relates in a straightforward way to the long-standing resolution criterion for crystalline specimens.

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