This effectively reduces the volume of the perceivable noise.Ī noise-cancellation speaker may be co-located with the sound source to be attenuated. This inverted signal (in antiphase) is then amplified and a transducer creates a sound wave directly proportional to the amplitude of the original waveform, creating destructive interference. Adaptive algorithms are designed to analyze the waveform of the background aural or nonaural noise, then based on the specific algorithm generate a signal that will either phase shift or invert the polarity of the original signal. Modern active noise control is generally achieved through the use of analog circuits or digital signal processing. The waves combine to form a new wave, in a process called interference, and effectively cancel each other out – an effect which is called destructive interference. A noise-cancellation speaker emits a sound wave with the same amplitude but with inverted phase (also known as antiphase) relative to the original sound. Sound is a pressure wave, which consists of alternating periods of compression and rarefaction. The technology is also used in road vehicles, mobile telephones, earbuds, and headphones. The concept was first developed in the late 1930s later developmental work that began in the 1950s eventually resulted in commercial airline headsets with the technology becoming available in the late 1980s. Graphical depiction of active noise reductionĪctive noise control ( ANC), also known as noise cancellation ( NC), or active noise reduction ( ANR), is a method for reducing unwanted sound by the addition of a second sound specifically designed to cancel the first. For deflecting noise in rocket launches, see Sound suppression system. For a muzzle device for a gun, see Silencer (firearms).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |