Active noise control

Graphical depiction of active noise reduction
Electronic noise management test in Vienna, 1973

Method for reducing unwanted sound by the addition of a second sound specifically designed to cancel the first.

- Active noise control

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Noise pollution

Propagation of noise with ranging impacts on the activity of human or animal life, most of them harmful to a degree.

A Qantas Boeing 747-400 passes close to houses shortly before landing at London Heathrow Airport.
Traffic is the main source of noise pollution in cities (like São Paulo, shown here).
Depiction of frequency weighting
A sound level meter is one of the main tools for measuring sounds in the environment and the workplace.
Noise level from a leaf blower, using the NIOSH Sound Level Meter app
The CityLink sound tube in Flemington, Melbourne, Australia, is designed to reduce roadway noise without detracting from the area's aesthetics.
A man inserting an earplug in his ear to reduce the noise exposure

The government of Sweden has taken soundproofing and acoustic absorbing actions, such as noise barriers and active noise control.

Noise-cancelling headphones

Integrating Sound Level Meter

Noise-cancelling headphones reduce unwanted ambient sounds using active noise control.

Lawrence J. Fogel

Pioneer in evolutionary computation and human factors analysis.

Charles Babbage, sometimes referred to as the "father of computing".

He is known as the inventor of active noise cancellation and the father of evolutionary programming.

Gun safety

Study and practice of using, transporting, storing and disposing of firearms and ammunition, including the training of gun users, the design of weapons, and formal and informal regulation of gun production, distribution, and usage, for the purpose of avoiding unintentional injury, illness, or death.

A Glock 19 disarmed and secured for transport (or storage) with a cable lock through its receiver
Example of safe firearm handling. The firearm is pointed at the ground and the handler's finger is off the trigger.
Trigger lock fitted to the trigger of a revolver

Some earmuffs or headphones made for shooting and similar loud situations use active noise control.

ISight

Brand name used by Apple Inc. to refer to cameras on various devices.

Apple iSight webcam
Apple iSight webcam
A built-in iSight on a White MacBook.

The iSight incorporates internal microphones with dual-element noise suppression.

Sony

Japanese multinational conglomerate corporation headquartered in Kōnan, Minato, Tokyo, Japan.

A Sony TR-730 transistor radio made in Japan, circa 1960
Sony Store in Nagoya, Japan
A rare Japanese market Betamax TV/VCR combo, the Model SL-MV1
First Sony Walkman TPS-L2 from 1979 (Expo in Sony Building at Ginza, Chuo-Ku, Tokyo)
Front side of a Sony 200GB Blu-ray disc
Sony at Westfield Riccarton shopping centre in Christchurch, New Zealand
The logo of Bravia television. Its backronym is "Best Resolution Audio Visual Integrated Architecture".
Notebook Sony Vaio. Sony has axed its loss-making PC business in 2014.
Xperia, the product device name for a range of smartphones from Sony.
Sony Interactive Entertainment headquarters in San Mateo, California
The PlayStation 2 is the best-selling video game console of all time
Sony Pictures Plaza, next to the main studio lot of Sony Pictures in Culver City, California
The main entrance to the Sony Pictures Entertainment studio lot in Culver City
Sony Music Entertainment headquarters in New York City, United States
Headquarters of Sony Financial Group in Tokyo, Japan

Sony is a major audio products manufacturer and one of the active noise control technology leaders.

Bose Corporation

American manufacturing company that predominantly sells audio equipment.

Bose store in Century City
Bose store at the Hong Kong International Airport
Bose products at a Staples store
SoundLink Mini
QuietComfort 25 headphones
ProFlight aviation headset

The wheels are raised when approaching a bump (or lowered into a pothole) to keep the vehicle level, using similar principles to noise cancelling audio devices.

Vehicle audio

Equipment installed in a car or other vehicle to provide in-car entertainment and information for the vehicle occupants.

A DIN head unit with radio and CD
1937 Philips Auto Radio. Weighing 24 kg and taking 8 litres of space, it was floor mounted with a wired remote control to be fitted to the dashboard.
A 1950s Philips car radio using both transistor and valves. This model used a range of valves that only required 12 volts for their plate (anode) voltage.<ref>{{cite web |title=6DS8 |url= http://www.r-type.org/exhib/aaa0246.htm |website=r-type.org |date=28 January 2019 |access-date=25 March 2021}}</ref>
GM Delco Transistorized "Hybrid" (vacuum tubes and transistors), first offered as an option on the 1956 Chevrolet Corvette car models
A car stereo head unit in a dashboard
1942 Lincoln Continental Cabriolet radio
Dashboard of VW Hebmüller with Telefunken Radio (1949/50)
1964 Mercedes-Benz W110 190c dashboard with original FM Blaupunkt "Frankfurt" head unit.
Blaupunkt Köln Radio - German 1958 Ford Taunus 17M P2 deLuxe
1990 Ford Sierra CLX Radio-Cassette head unit in a dashboard with cassette storage
1978 AMC Matador sedan factory AM-FM-stereo-8-track unit with an album by The Blues Brothers
A set of speaker drivers removed from a passenger vehicle
A car audio amplifier
Two 10-inch subwoofers in the trunk of a car
As technology keeps evolving, head units are now paired with the climate control system and other functions

The same loudspeakers may also be used to minimize road and engine noise with active noise control, or they may be used to augment engine sounds, for instance making a smaller engine sound bigger.

Portable media player

Portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files.

A flash-based player (Creative MuVo)
An embedded hard drive-based player (Creative ZEN Vision:M)
An MP3 CD player (Philips Expanium)
Rio PMP300, one of the earliest marketed DAPs, plays music in the MP3 format
The third generation iPod stores audio files on a miniature hard disk drive.
The Archos Jukebox 6000 released late 2001 was a DAP with a hard disk, one of the earliest of its kind
PlayStation Portable
A recent player, Sony Walkman NW-A35, focusing on audiophilic capabilities such as the ability to play Direct Stream Digital (DSD)
Sony Walkman NW-A1000, one of the earliest Walkman players that played MP3 alongside the proprietary ATRAC format
Toshiba Gigabeat running Portable Media Center, allowing video playback
An iRiver iFP-190 player, with a built-in microphone for voice recording
Rockbox, a popular free and open source firmware for various PMPs
Interior of a small unbranded flash-based DAP
The Iriver SPINN portable media player features Samsung storage and a Telechips processor. It also features both touchscreen and a clickwheel mechanism for navigation. The SPINN implements haptic feedback by vibrating with user input. Additional hardware capabilities enable it to decode the MPEG-4 Part 2 format and play back audio using SRS WOW.
An "MP4 player" from Newsmy, a major PMP manufacturer in China
A Sansa Clip player with a clip to attach on a person's clothing
An iPod Shuffle DAP, featuring no display screen
Connecting a computer to a Sansa Clip DAP to transfer content by "syncing"
An early DAP (NETrax, from 1999) in its dedicated docking station for charging and connecting to a PC

Some media players are used with Noise-cancelling headphones that use Active noise reduction to remove background noise.

Saab 340

Swedish twin-engine turboprop aircraft designed and initially produced by Saab AB and Fairchild Aircraft.

Saab 340 operated by Loganair for Flybe, gear up
2+1 passenger cross-section
Planform view showing straight wing
Saab 340 AEW&C with Erieye radar
SprintAir freighter with obstructed windows
Japan Coast Guard SAR variant with ventral radome
Cockpit in flight
Freighter interior

In 1989, an improved version of the airliner, the second generation 340B, introduced more powerful engines and wider horizontal stabilizers; later production 340Bs also featured an active noise control system.