Active Noise Canceling (ANC) is a technology used to reduce or eliminate unwanted background noise in audio devices such as headphones, earbuds, and speakers. It works by using microphones to pick up external sounds, analyze the noise, and then generate sound waves that are the opposite or “negative” of the original noise. These negative sound waves are then reproduced through the speakers, effectively canceling out the original noise.
Where did the ANC come from?
The history of Active Noise Cancellation (ANC) dates back to the early 20th century. One of the earliest known examples of ANC technology was developed in the 1920s by Bell Telephone Laboratories, which used a system of microphones and speakers to suppress noise on telephone lines.
In the 1950s, the U.S. Army began experimenting with ANC on aircraft to reduce noise levels for pilots. This led to the development of the first active noise-canceling headsets for pilots that used microphones to pick up external noise and speakers to generate opposing sound waves to cancel out noise.
In the decades that followed, ANC technology continued to evolve and improve, with various industries exploring its potential applications. In the 1970s, ANC was used in industry to reduce noise in factories and power plants, and in cars in the 1980s to reduce road noise.
In the 1990s, consumer audio products began to use ANC technology. Bose was one of the first companies to introduce consumer noise-canceling headphones in the 2000s, which became popular with travelers looking for a better listening experience on planes and trains.
In recent years, ANC has become increasingly popular with consumers and is now a common feature in many types of audio devices, including headphones, earbuds, and speakers. With the advancement in technology, the effectiveness of ANC has also improved, which is now considered a useful tool for reducing background noise in various environments.
In general, active noise cancellation has a long history of development and evolution beginning in the early 20th century, initially for military applications and then in industrial and consumer audio products. It is now a popular feature in many audio devices and continues to be refined and improved as technology advances.
How ANC works
There are two main types of ANC: Feedforward and Feedback.
Feedforward ANC uses a microphone located on the outside of the headphones, usually on the outside of the device. This microphone picks up external noise and sends it to the processor, which then generates negative sound waves to eliminate it. This type of ANC is typically found in over-ear headphones and is considered more effective at canceling out low-frequency sounds such as airplane engine sounds or construction site noise.
ANC feedback, also known as “closed-loop” ANC, uses a microphone placed inside the headphones or earbuds, close to the ear. This microphone picks up both external noise and sound played through speakers. The processor then compares the external noise with the audio being played and generates negative sound waves to eliminate the noise. This type of ANC is typically found in in-ear headphones and is considered more effective at eliminating high-frequency sounds such as the human voice.
What affects the effectiveness of the ANC
To work well, ANC technology requires a good noise floor, which is the minimum level of background noise the device can pick up. The better the noise floor, the more effective the ANC will be. Simply put – the greater the noise, the better its attenuation. In addition, many factors can affect the effectiveness of ANC, such as the type and quality of the microphone, the computing power of the device, and the fit of headphones or earbuds. In addition, the type of noise and environment can also affect the performance of the ANC.
ANC can be beneficial in many situations, such as when you want to focus on work in a noisy office or when you want to sleep on a plane or train. It can also be helpful for people with hearing loss or for those who are sensitive to loud or sudden sounds. Overall, ANC is a complex technology that uses advanced algorithms and signal processing to eliminate unwanted noise. It has become a popular feature on many audio devices and is considered a useful tool to enhance the listening experience in a variety of environments. However, the effectiveness of ANC can vary depending on the device, the type of noise, and the person’s hearing.
Disadvantages of ANC technology
ANC requires additional power, so mobile devices will drain their batteries faster when using this feature. Headphones with ANC are more expensive than those without this technology. The effectiveness of ANC may vary depending on the device, the type of noise, and the person’s hearing. Some people may find that it doesn’t work as well as they expected, or that it doesn’t completely eliminate all background noise. ANC is usually more effective at reducing low-frequency noise, such as the rumble of an aircraft engine, than higher-frequency noise, such as human speech.
There is also one serious problem. Over-reliance on ANC can lead to a lack of situational awareness and make it difficult to hear important sounds such as horns, emergency sirens, etc.