Consumer & Gadgets

Raspberry Pi unveils $50 interchangeable-lens camera board

Raspberry Pi's new high quality camera doesn't sport a fancy name—it's actually called "High Quality Camera"—but it packs some new features do-it-yourselfers are sure to enjoy, and it's being offered at Raspberry's typical ...

Hi Tech & Innovation

A short first hop for 'drone taxi' in Vienna

It was more of a small step than a giant leap, but the first public outing of a pilotless "drone taxi" in Vienna on Thursday nevertheless offered a glimpse into the possible future of urban travel.

Telecom

Compact amplifier could revolutionise optical communication

Researchers at Chalmers University of Technology, Sweden, present a unique optical amplifier that is expected to revolutionize both space and fiber communication. The new amplifier offers high performance, is compact enough ...

Engineering

'Impossible' millimeter wave sensor has wide potential

Researchers at the University of California, Davis, have developed a proof-of-concept sensor that may usher in a new era for millimeter wave radars. In fact, they call its design a "mission impossible" made possible.

Consumer & Gadgets

Team develops bracelet that jams microphones

The very topic of digital assistants and home smart devices sporting microphones and the potential for the outside world to listen in on recordings is not a comfortable one, to say the least. It's no longer a simple case ...

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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