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Acoustic sources within the "jet pipe" also contribute to the noise, mainly at lower speeds, which include combustion noise, and sounds produced by interactions of a turbulent stream with fans, compressors, and turbine systems. [1] The jet mixing sound is created by the turbulent mixing of a jet with the ambient fluid, in most cases, air.
Neuronal activity at the microscopic level has a stochastic character, with atomic collisions and agitation, that may be termed "noise." [4] While it isn't clear on what theoretical basis neuronal responses involved in perceptual processes can be segregated into a "neuronal noise" versus a "signal" component, and how such a proposed dichotomy could be corroborated empirically, a number of ...
The visual system becomes more sensitive to light and can amplify noise or minor changes in visual signals. For example to the work of different types of photoreceptors in the retina of the eye. In the dark, the rod photoreceptors, which are responsible for the perception of light in low light, are mainly activated, but they are not able to ...
The visual effect is described as the loss of vision as the brain cuts off the unchanging signal from the eyes. The result is "seeing black", [ citation needed ] an apparent sense of blindness. A flickering ganzfeld causes geometrical patterns and colors to appear, and this is the working principle for mind machines and the dream machine .
Noise-generating aircraft propeller. Aircraft noise is noise pollution produced by an aircraft or its components, whether on the ground while parked such as auxiliary power units, while taxiing, on run-up from propeller and jet exhaust, during takeoff, underneath and lateral to departure and arrival paths, over-flying while en route, or during landing.
Individuals with exploding head syndrome hear or experience loud imagined noises as they are falling asleep or are waking up, have a strong, often frightened emotional reaction to the sound, and do not report significant pain; around 10% of people also experience visual disturbances like perceiving visual static, lightning, or flashes of light.
Noise pollution, or sound pollution, is the propagation of noise or sound with potential harmful effects on humans and animals.The source of outdoor noise worldwide is mainly caused by machines, transport and propagation systems.
Noise has been associated with important cardiovascular health problems, particularly hypertension, as it causes an increase in levels of stress hormones and vascular oxidative stress. [2] [20] [21] [22] Noise levels of 50 dB(A) or greater at night may increase the risk of myocardial infarction by chronically elevating cortisol production. [23 ...