What Are Noise Cancelling Headphones?
Noise-cancelling headphones are designed to reduce unwanted ambient sounds, allowing the listener to enjoy audio content without the need to crank up the volume. They achieve this through active noise control (ANC), a technology that uses microphones and speakers to counteract external noise.
How Do Noise Cancelling Headphones Work?
To understand how noise cancelling headphones work, we need to look at the concept of sound waves. Sound travels in waves, which have peaks and troughs. When two sound waves of the same frequency meet, they can either amplify each other (constructive interference) or cancel each other out (destructive interference).
Noise cancelling headphones use destructive interference to eliminate unwanted noise. Here’s a step-by-step breakdown of how they achieve this:
Microphones Capture External Noise:
Noise cancelling headphones have small microphones built into the ear cups (for over-ear models) or earbuds (for in-ear models). These microphones pick up external sounds and pass the audio signal to the onboard processor.
Audio Processor Inverts the Sound Wave:
The processor takes the external noise and creates an inverted version of the sound wave. This inverted wave is the exact opposite of the noise wave.
Speakers Play the Inverted Wave:
The inverted sound wave is then played through the headphones’ speakers. When the original noise wave from the environment meets this inverted wave, the two cancel each other out due to destructive interference.
Resulting in Silence or Quieter Environment:
The end result is significantly reduced background noise, allowing the listener to focus on their audio content or simply enjoy peace and quiet.
While ANC technology is highly effective, it’s not perfect. Some high-frequency noises, like human voices, can still be heard, albeit at a much lower volume. That’s why many noise cancelling headphones also feature passive noise isolation through materials that physically block out sound.
The History of Noise Cancelling Technology
The journey of noise-canceling technology is fascinating, starting from military applications to becoming a staple in consumer electronics.
Early Beginnings in the Military
The concept of active noise cancellation was first explored in the 1950s. Dr. Lawrence Fogel is often credited with pioneering this technology. He was one of the first to develop a system for canceling noise in helicopter and airplane cockpits to protect pilots’ hearing and improve communication.
Later, in the 1970s, Dr. Amar Bose, the founder of Bose Corporation, became interested in noise cancellation during a flight. Frustrated by the engine noise, he imagined a headset that could cancel out this unwanted sound. This led to the development of the first prototype noise-cancelling headphones.
The First Consumer Models
In 1989, Bose released the first commercially available noise cancelling headphones, the Bose Aviation Headset, designed specifically for pilots. It wasn’t until the early 2000s that noise cancelling headphones became available to the general consumer market, with models like the Bose QuietComfort line leading the way.
As technology advanced, noise cancelling headphones became more effective, affordable, and widely available. Today, they’re a common accessory for anyone who values high-quality audio and a quieter listening experience.
An Explosion of Popularity in the 2000’s
Noise-canceling headphones surged in popularity around 2010 due to a combination of technological advancements, increasing consumer demand for better audio experiences, and the growth of the mobile device market. Noise-canceling technology started becoming mainstream as it became more effective and affordable. Companies like Bose, Sony, and Sennheiser were pioneers in refining this technology, making it accessible to a broader audience. particularly Bose who dominated the travel segment for sometime where you would literally see a set of Bose QC headphones on every traveller in the airports.
The rise of smartphones and portable music players, like the iPod, made listening to music on the go more common. Commuters, travelers, and office workers sought ways to create personal sanctuaries amidst the growing noise pollution in urban environments. Noise-canceling headphones offered a solution, providing users with an immersive listening experience by reducing background noise, enhancing the clarity of music and podcasts.
Moreover, advancements in battery technology allowed for longer usage times, and the headphones became lighter and more comfortable, further driving their adoption. As people increasingly traveled for work and leisure, the demand for noise-canceling headphones grew, establishing them as a must-have accessory for a generation seeking both quality sound and a reprieve from the chaos of daily life.
