Search results
Results From The WOW.Com Content Network
It is often caused by feedback in an amplifying device. The problem occurs notably in RF, [1] audio, and other electronic amplifiers [2] as well as in digital signal processing. [3] It is one of the fundamental issues addressed by control theory. [4] [5] [6] Parasitic oscillation is undesirable for several reasons.
One of the causes of intersymbol interference is multipath propagation in which a wireless signal from a transmitter reaches the receiver via multiple paths. The causes of this include reflection (for instance, the signal may bounce off buildings), refraction (such as through the foliage of a tree) and atmospheric effects such as atmospheric ducting and ionospheric reflection.
These phenomena can potentially generate vibrations of the ferromagnetic, conductive parts, coils and permanent magnets of electrical, magnetic and electromechanical device, resulting in an audible sound if the frequency of vibrations lies between 20 Hz and 20 kHz, and if the sound level is high enough to be heard (e.g. large surface of ...
In electronics, motorboating is a type of low frequency parasitic oscillation (unwanted cyclic variation of the output voltage) that sometimes occurs in audio and radio equipment and often manifests itself as a sound similar to an idling motorboat engine, a "put-put-put", in audio output from speakers or earphones.
Sound waves in air, in a tube. Sound waves in a solid experience a phase reversal (a 180° change) when they reflect from a boundary with air. [2] Sound waves in air do not experience a phase change when they reflect from a solid, but they do exhibit a 180° change when reflecting from a region with lower acoustic impedance. An example of this ...
Analyze the frequency of the voice's ess sound by sampling several instances and calculating the range of ess frequencies. Male voices sibilance range in 3–6 kHz, while female voice's typically range in 6–8 kHz. [3] Apply an equalization filter to quiet the determined frequency band by −4 dB to −11 dB during ess-frequency time events.
Only sound with parallel collinear phase velocity vectors interfere to produce this nonlinear effect. Even-numbered iterations will produce their modulation products, baseband and high frequency, as reflected emissions from the target. Odd-numbered iterations will produce their modulation products as reflected emissions off the emitter.
An acousto-optic modulator (AOM), also called a Bragg cell or an acousto-optic deflector (AOD), uses the acousto-optic effect to diffract and shift the frequency of light using sound waves (usually at radio-frequency). They are used in lasers for Q-switching, telecommunications for signal modulation, and in spectroscopy for frequency