Engineering

Army computer models unveil secret to quieter small drones

It's no secret the U.S. Army wants its small unmanned aerial systems to operate quietly in densely-populated regions, but tests to achieve this can be expensive, time-consuming and labor-intensive according to researchers.

Engineering

Headset over headphone: Canceling unnecessary and unwanted noise

Reporting in the journal Scientific Reports, the team of Tong Xiao, Xiaojun Qiu and Benjamin Halkon highlight the positive impacts for health and wellbeing of their 'virtual Active Noise Control/Cancelation (ANC) headphone' ...

Engineering

New system uses floor vibrations to detect building occupants

Thanks to a new system developed at EPFL, building owners can detect the number of occupants and track their movement using sensors installed on floor slabs. This novel approach could be particularly useful for enhancing ...

Engineering

Reducing noise transmitted through an open window

A new device that can reduce the intensity of sound passing through open windows is presented in a proof-of-principle study in Scientific Reports. It fits into a two-panel sliding window and can decrease the perceived loudness ...

Consumer & Gadgets

Noise-cancellation comes to Google Meet

Google is making noise this week—or should we say it's making no noise—with its rollout of a new feature for its video-conferencing app Meet.

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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