Editing Active noise control (section)

== History ==
[[File:Electronen-politie bestrijdt lawaai in Wenen, Bestanddeelnr 926-2980 (cropped).jpg|thumb|Electronic noise management test in Vienna, 1973]]
The first patent for a noise control system—{{US patent|2043416}}—was granted to inventor Paul Lueg in 1936. The patent described how to cancel sinusoidal tones in ducts by phase-advancing the wave and canceling arbitrary sounds in the region around a loudspeaker by inverting the polarity.<ref name="auto">{{Cite web |url=http://hdl.handle.net/10919/27111 |title=Evaluation of an Improved Active Noise Reduction Microphone using Speech Intelligibility and Performance-Based Testing, n.d. |date=24 April 2002 |hdl=10919/27111 |access-date=2020-09-23 |archive-url=https://web.archive.org/web/20151026054112/http://scholar.lib.vt.edu/theses/available/etd-04222002-143554/unrestricted/02rudissertation.pdf |archive-date=2015-10-26 |url-status=dead |last1=Urquhart |first1=Ryan L. }}</ref> In the 1950s [[Lawrence J. Fogel]] patented systems to cancel the noise in helicopter and airplane cockpits. In 1957 Willard Meeker developed a working model of active noise control applied to a circumaural earmuff. This headset had an active attenuation bandwidth of approximately 50–500&nbsp;Hz, with a maximum attenuation of approximately 20&nbsp;dB.<ref name="auto"/> By the late 1980s the first commercially available active noise reduction headsets became available. They could be powered by [[Nickel–cadmium battery|NiCad batteries]] or directly from the aircraft power system.