Search results
Results from the WOW.Com Content Network
The report "A Review of Published Research on Low Frequency Noise and its Effects" [54] contains a long list of research about exposure to high-level infrasound among humans and animals. For instance, in 1972, Borredon exposed 42 young men to tones at 7.5 Hz at 130 dB for 50 minutes.
Low frequency (LF) is the ITU designation [1] [2] for radio frequencies (RF) in the range of 30–300 kHz. Since its wavelengths range from 10–1 km , respectively, it is also known as the kilometre band or kilometre wave s.
Radio noise near in frequency to a received radio signal (in the receiver's passband) interferes (RFI) with the operation of the receiver's circuitry.The level of noise determines the maximum sensitivity and reception range of a radio receiver; if no noise were picked up with radio signals, even weak transmissions could be received at virtually any distance by making a radio receiver that had ...
Zener diode based noise source. A noise generator is a circuit that produces electrical noise (i.e., a random signal). Noise generators are used to test signals for measuring noise figure, frequency response, and other parameters. Noise generators are also used for generating random numbers. [1]
Extremely low frequency (ELF) is the ITU designation [1] for electromagnetic radiation (radio waves) with frequencies from 3 to 30 Hz, and corresponding wavelengths of 100,000 to 10,000 kilometers, respectively. [2] [3] In atmospheric science, an alternative definition is usually given, from 3 Hz to 3 kHz.
If the noise source is correlated with the signal, such as in the case of quantisation error, the intentional introduction of additional noise, called dither, can reduce overall noise in the bandwidth of interest. This technique allows retrieval of signals below the nominal detection threshold of an instrument.
It can be heard as low-frequency noise and becomes a serious problem when playing records on audio systems with a good low-frequency response. Even when not audible, rumble can cause intermodulation, modulating of the amplitude of other frequencies. The ‘unweighted’ response curve is intended for use in assessing the level of inaudible ...
Very low frequency or VLF is the ITU designation [1] [2] for radio frequencies (RF) in the range of 3–30 kHz, corresponding to wavelengths from 100 to 10 km, respectively. The band is also known as the myriameter band or myriameter wave as the wavelengths range from one to ten myriameters (an obsolete metric unit equal to 10 kilometers).