News tagged with noise

X-ray noise reduction technology cuts radiation

(HealthDay)—For patients undergoing coronary angiography and coronary angioplasty, a new X-ray technology with an image noise reduction algorithm reduces radiation exposure, according to research published in the Aug. 1 ...

Jul 21, 2016
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Traffic noise increases the risk of heart attack

Your risk of heart attack increases with the amount of traffic noise to which you are exposed. The increase in risk - though slight - is greatest with road and rail traffic noise, less with aircraft noise. Such are the conclusions ...

Jul 08, 2016
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Quiet please in the intensive care unit

A study presented at Euroanaesthesia 2016 shows that noise levels in the Intensive Care Unit (ICU) can go well above recommended levels, disturbing both patients and the medical teams that care for them. The study is by Dr ...

May 30, 2016
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Noise

In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise ("static") heard when listening to a weak radio transmission with significant electrical noise. Signal noise is heard as acoustic noise if the signal is converted into sound (e.g., played through a loudspeaker); it manifests as "snow" on a television or video image. High noise levels can block, distort, change or interfere with the meaning of a message in human, animal and electronic communication.

In signal processing or computing it can be considered random unwanted data without meaning; that is, data that is not being used to transmit a signal, but is simply produced as an unwanted by-product of other activities. "Signal-to-noise ratio" is sometimes used to refer to the ratio of useful to irrelevant information in an exchange.

In biology, noise can describe the variability of a measurement around the mean, for example transcriptional noise describes the variability in gene activity between cells in a population.

In many cases, the special case of thermal noise arises, which sets a fundamental lower limit to what can be measured or signaled and is related to basic physical processes described by thermodynamics, some of which are expressible by simple formulae.

In some fields, noise means unwanted information or data that is not relevant to the hypothesis or theory being investigated or tested.

This text uses material from Wikipedia, licensed under CC BY-SA

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